WASHINGTON (AP) — Secretary of State Antony Blinken said he spoke to Russian Foreign Minister Sergey Lavrov by phone on Friday and urged Moscow to accept a U.S. offer to release WNBA star Brittney Griner and another American detainee, Paul Whelan.

It was Blinken's first talk with his Russian counterpart since before Russia's invasion of Ukraine in February.

Blinken did not provide details of Lavrov’s response to what he had previously called a “substantial proposal." Blinken had publicly requested the call and revealed the existence of the offer to Russia — which people familiar with it say involves a swap for Whelan and Griner with convicted Russian arms dealer Viktor Bout.

Blinken described the call as “a frank and direct conversation” centered primarily on the proposal for the release of the Americans.

“I urged Foreign Minister Lavrov to move forward with that proposal," he said. "I can’t give you an assessment of whether that is any more or less likely.”

Blinken also said he had pressed Lavrov on the importance of Russia following through on an agreement to allow Ukrainian grain shipments to leave the Black Sea and warned him of consequences should Moscow move ahead with suspected plans to annex portions of eastern and southern Ukraine.

Blinken said he told Lavrov that the world will “never recognize” any annexation of Ukrainian territory, which he said would “will result in significant additional costs for Russia.”

He declined to comment on how Lavrov replied to his messages.

“I don’t want to characterize any of Foreign Minister Lavrov’s responses," he stated.

The U.S. and its allies restart Iran nuclear talks on Monday unsure how Tehran's new government will approach negotiations, not optimistic about the prospects ahead and emphasizing that if diplomacy fails, the U.S. is "prepared to use other options."

The parties to the Joint Comprehensive Plan of Action will reconvene in Vienna after almost six months to discuss a mutual return to the deal by both the U.S. and Iran, but the hiatus has given time for new obstacles to take root.

Video above: Trump's Iran deal exit 'very bad judgments,' Biden said earlier this month

On Friday, Iran announced yet more advances in its uranium enrichment, which reduces the amount of time Tehran would need to develop a nuclear weapon, if it chooses to, an announcement clearly meant to give Iran leverage when it arrives in Vienna for talks.

Other parties to the agreement -- including Germany, the UK, Britain, France, China and Russia -- are coming into the talks calling for negotiations to pick up where they left off. European sources tell CNN they expect the Iranians to treat the meeting as "round one." U.S. officials have expressed similar concerns.

The recently elected hardline government in Tehran will send a new set of negotiators to Vienna who have been emphasizing the need for complete U.S. sanctions relief, not compliance with the deal, while U.S. officials have said they have absolutely no plans to offer Iran incentives to talk.

'The time to choose is short'

And senior U.S. officials have repeatedly warned that if advances in Iran's nuclear program and enrichment capability continue unabated, they could render the benefits of the JCPOA moot -- a development that would force the U.S. to pursue other options.

"We are still hopeful that diplomacy can find a way," Brett McGurk, the National Security Council's coordinator for the Middle East and North Africa, told the Manama Dialogue organized by the International Institute for Strategic Studies. "But if it cannot find a way, we are prepared to use other options."

"There is no question, we are not going to allow Iran to get a nuclear weapon, period," McGurk said. "And when it came to military force for behavior change, that is a pretty fuzzy objective for a military force. When it comes to military force to prevent a country from obtaining a nuclear weapon, that is a very achievable objective."

U.S. Special Envoy for Iran Rob Malley said in a tweet after a Nov. 18 meeting with Middle Eastern allies and European parties to the deal that Iran could choose one of two paths: "continued nuclear escalation & crisis, or mutual return to the JCPOA, creating opportunities for regional economic & diplomatic ties."

"Time to choose is short," Malley wrote.

Sources familiar with preparations for the talks say that the parties were closely watching International Atomic Energy Agency director Rafael Grossi's visit to Tehran last week, seeing it as an indication of Iran's approach to the talks in Vienna, those sources said. Grossi told the IAEA board afterward that the talks were "inconclusive."

One of the contentious issues remaining is that Iran is refusing inspectors from the IAEA monitoring access to the Karaj centrifuge production facility, which reports suggest has resumed operations.

"This is seriously affecting the [IAEA's] ability to restore continuity of knowledge at the [Karaj] workshop, which has been widely recognized as essential in relation to a return to the JCPOA," Grossi told a Board of Governors meeting on Wednesday.

The Arms Control Association noted that Iran's refusal to allow the IAEA to install new cameras or confirm that production hasn't restarted could undermine attempts to revitalize the JCPOA and its strict verification regime if it isn't possible to fully complete records of Iran's nuclear program. Tehran's refusal to grant access to Karaj also drives speculation and concern about what, exactly, Iran is doing, the ACA said.

'No choice'

On Thursday, the U.S. Mission to International Organizations in Vienna told the IAEA meeting that "if Iran's non-cooperation is not immediately remedied ... especially the restoration of continuity of knowledge at Karaj, the Board will have no choice but to reconvene in extraordinary session before the end of this year in order to address the crisis."

Meanwhile, on Friday, Iran announced its stock of 60% enriched uranium has grown to 66 pounds and its amount of 20% enriched uranium had also increased. Both levels are much closer to weapons-grade uranium which is enriched above 90%.

According to the Arms Control Association, enriching uranium to 20% "constitutes about 90 percent of the necessary work to enrich to weapons-grade."

As Iran's stockpiles grow, the ACA says, its breakout time, or the time it would take to produce enough uranium enriched to weapons-grade for one bomb, decreases. The ACA estimates that Iran's current breakout time is likely about one month, down from 12 months when the JCPOA was fully implemented.

Enrichment was limited under the JCPOA, which the U.S. left unilaterally in May 2018 under former President Donald Trump. Iran restarted enrichment last year to pressure the U.S. to ease sanctions.

'A very uncertain proposition'

State Department spokesman Ned Price reflected the ambiguity surrounding the resumed talks on Nov. 22, calling the mutual return to compliance with the JCPOA "a very uncertain proposition."

The next day, Price told reporters in Washington that, "it is our hope that the new government in Iran shows up in Vienna and shows up in Vienna ready to negotiate in good faith to build on the progress that had been achieved in the previous six rounds of negotiations."

But he added that the U.S. has "been very clear that we are not prepared to take unilateral steps solely for the benefit of greasing the wheel" to get the talks going again. Former President Donald Trump pulled the U.S. from the deal in 2018.

Sources familiar with the preparations for the talks have told CNN that the U.S. and its allies are not at a point where they would begin offering Iran confidence-building measures, but one official said there is a possibility the U.S. and its allies could employ them down the road. As a result, incentives for Iran won't be discussed at this week's meetings in Vienna, where the U.S. and allies will be focused on simply taking the temperature and seeking to advance from where they left off months ago, U.S. and European sources explained.

'Plan B'

Everyone involved in the talks is mindful of the ticking clock. The sources told CNN that there's still time to reach a deal, but it would likely run out by the end of next year. For now, they said there is no hard and fast "Plan B" yet.

Critics of the deal say that the Biden administration has sacrificed leverage by easing pressure on Iran while it builds up its nuclear program.

"The Biden administration's Iran policy is failing, and without a significant course correction that policy will either result in Iranian nuclear weapons or in a war to stop that development," said Mark Dubowitz, the CEO of Foundation for Defense of Democracies. Dubowitz argued that the administration's approach will allow Iran to rebuild toward a "lethal end state" of with pathways to nuclear weapons and a robust nuclear infrastructure.

"Israel is going to have no choice but to use military force to stop Iran's nuclear weapons before Tehran reaches this lethal end state," Dubowitz said.

Israeli Prime Minister Naftali Bennett has been making clear that Israel will be prepared to act if necessary. Addressing delegates at a security conference near Tel Aviv on Tuesday, Bennett said that "if there is a return to the JCPOA, Israel obviously is not a party to the agreement and is not obligated by it."

Bennett complained that after the nuclear deal was signed in 2015, the "State of Israel simply went to sleep. We were occupied with other things. We will learn from this mistake. We will maintain our freedom of action," he said.

Western officials have tried to argue to the Israelis that attacks on Israel's nuclear program are not very useful when the overall goal is to come up with a comprehensive solution, and especially when the Iranians have sped up their capability to rebuild after attacks, sources familiar with the Iran talks have told CNN.

Western officials have also raised the danger of Iran responding with kinetic action, but sources familiar with the talks say Israeli officials still seem to think that it is still an effective tool to show their capabilities.

Asked about those warnings, Price said that, "at the end of the day, the United States and Israel, we share a common objective here, and that is to see to it that Iran is verifiably and permanently prevented from obtaining a nuclear weapon. And we continue to believe that diplomacy in coordination with our allies and partners -- and that, of course, includes Israel -- is the best path to achieve that goal."

"We've also been very clear that this is not a process that can go on indefinitely and if the Iranians through their actions or through their inactions demonstrate or suggest that they lack that good faith, that they lack that clarity of purpose, we'll have to turn to other means," Price said Tuesday. "We have a variety of other means we're discussing those with our allies and partners."

Diplomatic flurry

In recent weeks, U.S. officials have conducted a flurry of diplomacy with regional powers and other parties to the deal, working to forge a united front.

President Joe Biden met with European partners to discuss Iran during the June G7 meetings in the UK. In recent weeks, Secretary of State Antony Blinken has also conferred with European allies, as well as China and Russia, on Iran. And Malley recently met with Gulf countries, Israeli officials and European partners in the JCPOA.

"I think the Iranians believe they have some eastward option with Russia and China in which they can circumvent the pressure of sanctions," McGurk said on Sunday. "And that is just wrong. And so I think we are approaching the talks at the end of November as a pretty united front with the P5+1."

Antony Blinken addressed reporters for the first time as secretary of state on Wednesday, hours after being sworn in, and said the Biden administration has already challenged Russia on several human rights violations.

Namely, Blinken said that the arrest of Russian opposition leader Aleksey Navalny was concerning. Navalny was arrested by Russian authorities on January 17, prompting protests from those who oppose Vladimir Putin’s government.

Blinken said that the US has a “deep concern” for Navalny’s safety and security, and that his voice represents many Russians.

OVD-Info, a human rights group that tracks political oppression, reported 3,980 arrests stemming from last weekend’s protests. The protests spread throughout Russia, with 1,544 of the arrests occurring in Moscow.

“We have already expressed our deep concern for the treatment of Navalny specifically, and more generally the human rights situation in Russia,” Blinken said. “It remains striking to me how concerned, and maybe even scared the Russian government seems to be of one man, Mr. Navalny.

“Across the board, as (President Joe Biden) has said, we’re reviewing all of these actions that are of deep concern of us, whether it is the treatment of Mr. Navalny, in particularly the use of a chemical weapon in an attempt to assimilate him.”

On Tuesday, the White House released a statement that Biden had a phone call with Putin, as Biden raised a number of concerns, “Including the SolarWinds hack, reports of Russia placing bounties on United States soldiers in Afghanistan, interference in the 2020 United States election, and the poisoning of Aleksey Navalny.”

Earlier this month, the US intelligence community released a statement that said Russia was the “likely actor” behind the SolarWinds hack. US intelligence officials said that 18,000 public and private sector computers were impacted by the breach. The US agencies said that 10 US government agencies were impacted.

“We’re very urgently looking into SolarWinds and its implications,” Blinken said. “We’re looking into reports of bounties placed by Russia on American forces in Afghanistan. And we’re looking at these questions of election interference.”

In August, the Office of the Director of National Intelligence released a statement outlining efforts by Iran, China and Russia to attempt to undermine this year’s presidential election.

“Ahead of the 2020 U.S. elections, foreign states will continue to use covert and overt influence measures in their attempts to sway U.S. voters’ preferences and perspectives, shift U.S. policies, increase discord in the United States, and undermine the American people’s confidence in our democratic process,” William Evanina, director of the United States National Counterintelligence and Security Center, said. "They may also seek to compromise our election infrastructure for a range of possible purposes, such as interfering with the voting process, stealing sensitive data, or calling into question the validity of the election results. However, it would be difficult for our adversaries to interfere with or manipulate voting results at scale.”

As part of Evanina’s assessment, he said that China and Iran were attempting to seek a favorable outcome for Biden, while Russia was working to ensure a favorable outcome for Trump.

Other notes from Wednesday’s briefing:

- Blinken said that he is encouraged by the Abraham Accords, which normalized relations between Israel, UAE and Bahrain. The Trump administration was active in brokering the agreement between the nations.

- "It is not a secret that the relationship between the United States and China is the most important in the world," Blinken said. He says the relationship has increasingly become adversarial, but says there are areas of mutual interest for both nations, including climate change.

- While Blinken is hopeful for the US to re-enter a nuclear agreement with Iran, Blinken said that an agreement will only come if Iran is in full compliance under the nuclear agreement that was in place prior to the Trump administration. Currently, Blinken said Iran is not in compliance with the multinational agreement what was signed in 2015 by the US, Iran, and several European nations.

Justin Boggs is a writer for the E.W. Scripps National Desk. Follow him on Twitter @jjboggs or on Facebook.