Ukrainian President Volodymyr Zelenskyy will join leaders of the world’s most powerful democracies in Hiroshima, Japan, making his furthest trip from his war-torn country as leaders are set to unveil new sanctions on Russia for its invasion.Oleksiy Danilov, the secretary of Ukraine’s National Security and Defense Council, confirmed on national television that Zelenskyy would attend the summit.“We were sure that our president would be where Ukraine needed him, in any part of the world, to solve the issue of stability of our country,” said Danilov. “There will be very important matters decided there, so physical presence is a crucial thing to defend our interests”.Japanese leader Fumio Kishida said he invited Zelenskyy to the G7 Summit during his visit to Kyiv in March.Video above: Biden says U.S. and Japan stand together in ‘holding Russia accountable for actions in Ukraine’Zelenskyy is also set to appear virtually at a Friday meeting of G7 leaders, where they are to get an update on battlefield conditions and agree to toughen their efforts to constrain Moscow’s war effort.The leaders of the world's most powerful democracies planned to devote much of the first full day of the Group of Seven summit to finding new ways to punish Russia for its 15-month invasion of Ukraine.Russian President Vladimir Putin's nuclear threats against Ukraine, along with North Korea's months-long barrage of missile tests and China's rapidly expanding nuclear arsenal, have resonated with Japan's push to make nuclear disarmament a major part of the summit. World leaders Friday visited a peace park dedicated to the tens of thousands who died in the world's first wartime atomic bomb detonation.After group photos and a symbolic tree planting, a new round of sanctions were to be unveiled against Moscow, with a focus on redoubling efforts to enforce existing sanctions meant to stifle Russia's war effort and hold accountable those behind it, a U.S. official said. Russia is now the most-sanctioned country in the world, but there are questions about the effectiveness of the financial penalties.The U.S. official, speaking on the condition of anonymity to preview the announcement, said the U.S. component of the actions would blacklist about 70 Russian and third-country entities involved in Russia's defense production, and sanction more than 300 individuals, entities, aircraft and vessels.The official added that the other G7 nations would undertake similar steps to further isolate Russia and to undermine its ability to wage war in Ukraine. Details were to emerge over the course of the weekend summit.The European Union was focused on closing the door on loopholes and plans to restrict trade in Russian diamonds, Charles Michel, president of the European Council, told reporters early Friday.He said the G7 would also try to convey to leaders of countries that are non-member guests at the summit why it's so important to enforce sanctions.Japanese Prime Minister Fumio Kishida, who represents Hiroshima in parliament, wants nuclear disarmament to be a major focus of discussions, and he will formally start the summit at Hiroshima's Peace Memorial Park. The visit by world leaders to a park dedicated to preserving reminders of Aug. 6, 1945, when a U.S. B-29 dropped an atomic bomb over Hiroshima, will be a striking image to start the summit. An estimated 140,000 people were killed, and a fast-dwindling number of now-elderly survivors have ensured that Hiroshima has become synonymous with anti-nuclear peace efforts.Video below: Japan's prime minister pushes nuclear disarmament at G7 summit“Honestly, I have big doubts if Mr. Kishida, who is pursuing a military buildup and seeking to revise the pacifist constitution, can really discuss nuclear disarmament,” Sueichi Kido, a 83-year-old “hibakusha” or survivor of the Nagasaki explosion, told The Associated Press. “But because they are meeting in Hiroshima I do have a sliver of hope that they will have positive talks and make a tiny step toward nuclear disarmament.”On Thursday night, Kishida opened the global diplomacy with a sitdown with President Joe Biden after Biden's arrival at a nearby military base. Kishida also held talks with British Prime Minister Rishi Sunak before the three-day gathering of leaders opens.The Japan-U.S. alliance is the "very foundation of peace and security in the Indo-Pacific region," Kishida told Biden in opening remarks. Japan, facing threats from authoritarian China, Russia and North Korea, has been expanding its military but also relies on 50,000 U.S. troops stationed in Japan and U.S. military might."We very much welcome that the cooperation has evolved in leaps and bounds," Kishida said.Biden, who greeted U.S. and Japanese troops at nearby Marine Corps Air Station Iwakuni before his meeting with Kishida, said: "When our countries stand together, we stand stronger, and I believe the whole world is safer when we do."As G7 attendees made their way to Hiroshima, Moscow unleashed yet another aerial attack on the Ukrainian capital. Loud explosions thundered through Kyiv during the early hours, marking the ninth time this month that Russian air raids have targeted the city after weeks of relative quiet."The crisis in Ukraine: I'm sure that's what the conversation is going to start with," said Matthew P. Goodman, senior vice president for economics at the Center for Strategic and International Studies.Speaking to reporters aboard Air Force One, Jake Sullivan, the White House national security adviser, said there will be "discussions about the battlefield" in Ukraine and on the "state of play on sanctions and the steps that the G7 will collectively commit to on enforcement in particular."The United States has frozen Russian Central Bank funds, restricted banks' access to SWIFT — the dominant system for global financial transactions -- and sanctioned thousands of Russian firms, government officials, oligarchs and their families.The Group of Seven nations collectively imposed a $60 per-barrel price cap on Russian oil and diesel last year, which the U.S. Treasury Department on Thursday defended in a new progress report, stating that the cap has been successful in suppressing Russian oil revenues. Treasury cites Russian Ministry of Finance data showing that the Kremlin's oil revenues from January to March this year were more than 40% lower than last year.The economic impact of sanctions depends largely on the extent to which a targeted country is able to circumvent them, according to a recent Congressional Research Service report. So for the past month, U.S. Treasury officials have traveled across Europe and Central Asia to press countries that still do business with the Kremlin to cut their financial ties."The challenge is to make sure the sanctions are painful against Russia, not against ourselves," said Michel. "It's very clear that each package is more difficult than the previous one and requires more political effort to make a decision."G7 leaders and invited guests from several other counties are also expected to discuss how to deal with China's growing assertiveness and military buildup as concerns rise that it could could try to seize Taiwan by force, sparking a wider conflict. China claims the self-governing island as its own and its ships and warplanes regularly patrol near it.Security was tight in Hiroshima, with thousands of police deployed throughout the city. A small group of protesters was considerably outnumbered by police as they gathered Wednesday evening beside the ruins of the Atomic Peace Dome memorial, holding signs including one which read "No G7 Imperialist Summit!"In a bit of dueling diplomacy, Chinese President Xi Jinping is hosting the leaders of the Central Asian countries of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan for a two-day summit in the Chinese city of Xi'an.The leaders are due to discuss efforts to strengthen the global economy and address rising prices that are squeezing families and government budgets around the world, particularly in developing countries in Africa, Asia and Latin America.Video below: President Joe Biden is in Japan for the G7 summit as U.S. debt ceiling approachesThe debate over raising the debt limit in the U.S., the world's largest economy, has threatened to overshadow the G7 talks. Biden plans to hurry back to Washington after the summit for debt negotiations, scrapping planned meetings in Papua New Guinea and Australia.The British prime minister arrived in Japan earlier Thursday and paid a visit to the JS Izumo, a ship that can carry helicopters and fighter jets able to take off and land vertically.During their bilateral meeting Thursday, Sunak and Kishida announced a series of agreements on issues including defense; trade and investment; technology, and climate change, Sunak's office said.The G7 includes Japan, the United States, the United Kingdom, France, Germany, Canada and Italy, as well as the European Union.A host of other countries have been invited to the summit in hopes of strengthening ties to non-G7 countries while shoring up support for efforts like isolating Russia.Leaders from Australia, Brazil, India, Indonesia and South Korea are among the guests. Ukrainian President Volodymyr Zelenskyy is expected to join by video link.__Associated Press writers Josh Boak, Adam Schreck and Mari Yamaguchi in Hiroshima, and Fatima Hussein in Washington contributed to this report.