KYIV, Ukraine — In a bitter and emotional speech, Ukraine President Volodymyr Zelenskyy criticized NATO for refusing to impose a no-fly zone over Ukraine, saying it will fully untie Russia’s hands as it escalates its attack from the air.

“All the people who die from this day forward will also die because of you, because of your weakness, because of your lack of unity,” he said in a nighttime address. “The alliance has given the green light to the bombing of Ukrainian cities and villages by refusing to create a no-fly zone.”

On Friday, NATO refused to impose a no-fly zone, warning that to do so could provoke widespread war in Europe with nuclear-armed Russia.

Zelenskyy said Ukrainians will continue to resist and have already destroyed Russia’s plans for a lightning invasion “having endured nine days of darkness and evil.”

“We are warriors of light,” he said. “The history of Europe will remember this forever.”

NATO countries are already on high alert. The U.S. has sent thousands of troops to the region in support of NATO countries. Article 5 of the North Atlantic Treaty references a collective defense, meaning an attack on one NATO member is an attack on all.