Ukrainian president agrees to talks as Putin puts his nuclear forces on alert

S E E D E D   C O N T E N T

President Vladimir Putin on Sunday ordered Russia's nuclear deterrent forces to be on high alert, ratcheting up tensions as Ukraine agreed to talks with Russian officials and the European Union moved to close its airspace to all Russian planes.

In a statement, Ukrainian President Volodymyr Zelenskyy said he had agreed to meet with the Russians on the border of Belarus "without preconditions" after speaking with that country's president, Alexander Lukashenko. Lukashenko, a Putin ally, "has taken responsibility for ensuring that all planes, helicopters and missiles stationed on Belarusian territory will remain on the ground during the Ukrainian delegation's travel, talks and return," Zelenskyy's office said.

Latest updates on Ukraine:

• The European Union announces it is closing its airspace to all Russian aircraft, while UPS and FedEx say they are suspending service to the country.
• Putin puts his military's nuclear deterrent forces on high alert after what he calls "aggressive statements" from the West.
• Ukraine agrees to negotiations with Russia on the border with neighboring Belarus.
• Kyiv remains in Ukrainian hands after fierce fighting; Ukraine says it took back controlof Kharkiv, the country's second-largest city.
• Russian forces block southern Ukrainian cities with the apparent aim of seizing the coastline.
• At least 368,000 Ukrainians are fleeing westward, becoming refugees near the border and in neighboring countries .
  

Zelenskyy had said his government would not attend negotiations in Belarus, a close ally of Moscow's, where thousands of Russian troops massed in the lead-up to the invasion last week. He later said he doubted the meeting, which was to take place near the Pripyat River, would produce results but that he went ahead with it "so that no citizen of Ukraine would have any doubt that I, as president, did not try to stop the war when there was a small chance." Zelenskyy added that he would remain in Kyiv while the talks proceeded.

Russia, like NATO and the U.S., has thousands of nuclear warheads in its arsenal. By putting nuclear deterrence forces on high alert for what he called the "aggressive statements" of NATO countries, Putin raised the global stakes of the conflict to a far deadlier level.

A senior Defense Department official suggested the nuclear readiness of NATO and Russia was not to be taken lightly, even amid a historic invasion. Putin's escalation, which the Pentagon had no reason to doubt, "could make things much, much, more dangerous," the official said Sunday during an evening briefing held on background.

White House press secretary Jen Psaki said in an earlier interview on MSNBC that Putin's move was "exactly the kind of manufactured threats" that he has been using since the invasion started "to justify further aggressive action."

Speaking on CBS' "Face the Nation," the U.S. ambassador to the United Nations, Linda Thomas-Greenfield, said Putin "is continuing to escalate this war in a manner that is totally unacceptable." The U.N. Security Council voted Sunday afternoon to convene a rare emergency special session of the General Assembly on Monday to address the Russian invasion.

E.U., U.S. sanctions

As the fighting continued into its fourth day, the president of the European Commission, Ursula von der Leyen, announced that the European Union would close its airspace to all Russian planes — a move that some European countries had taken individually. Von der Leyen also said the E.U. was banning Russian state media and sanctioning Belarus for its involvement in the invasion.

European leaders are also in step with the U.S. in efforts to target the assets of Russian oligarchs and sanctioned companies, a senior White House official said, adding that the Biden administration is launching a trans-Atlantic task force to identify any "ill-gotten gains" from elites close to Putin and the Russian government. That is in addition to severe sanctions placed on Putin's personal assets and Russian banks over the last several days.

Switzerland's president, Ignazio Cassis, also said Sunday that it was "very probable" his country would join the efforts to sanction Russia and freeze its assets.

With more and more flights out of Russia being canceled and swaths of airspace being shut down, the U.S. Embassy there urged all Americans in the country to depart "immediately." Separately, FedEx and UPS said they were suspending shipments to Russia, as well as Ukraine, and the British oil giant BP said it was abandoning its 20 percent stake in the Russian state-controlled oil company Rosneft.

The U.S. and the E.U.'s actions came after Washington and allies escalated sanctions on Russia over the weekend, including blocking certain Russian banks from accessing SWIFT, a service that facilitates global transactions among thousands of financial institutions. Japan also said Sunday that it would join that move.

Von der Leyen also said the E.U. would deliver military equipment to Ukraine in what she called "a watershed moment" — the first time the E.U. has financed the purchase and delivery of weapons for a country under attack. The move followed a decision by Germany and other countries to provide Ukraine with weapons and supplies. Ukrainian Foreign Minister Dmytro Kuleba, meanwhile, put out a new call Sunday for more weapons, including "more air-to-air and ground-to-air missiles to counter invaders. We need more drones, more vehicles, aircraft artillery, guns, machine guns, ammunition."

U.S. Embassy in Moscow: U.S. citizens should consider leaving Russia 'immediately'

Fierce fighting

Earlier in the day, Ukraine said it had taken back control of its second-largest city, Kharkiv, after fighting pitched street battles with the Russian forces, and Kyiv residents awoke to find that the capital was still in Ukrainian hands.

"Anyone who wants to join the defense of Ukraine, Europe and the world can come and fight side by side with the Ukrainians," Zelenskyy's office said in a statement. "There is no greater contribution which you can make for the sake of peace."

Kuleba,the foreign minister, echoed the call, inviting foreigners to contact Ukraine's foreign diplomatic missions in their respective countries.

Russian vehicles broke into Kharkiv, a city of 1.4 million people 25 miles south of the border with Russia, and engaged in intense street fighting with the Ukrainian forces. The head of the Kharkiv regional administration, Oleh Sinegubov, said later that Ukrainians had regained control of the city. "Control over Kharkiv is completely ours!" Sinegubov said in a message on the Telegram messaging app.

NBC News teams in the country witnessed Ukrainians rallying to repel the invaders, with chief foreign correspondent Richard Engel seeing people in the towns and villages he has passed filling sandbags, manning checkpoints and standing armed at crossroads.

The senior U.S. defense official said Sunday that the U.S. continues to see Russian momentum slowed by the stiff Ukrainian resistance and logistical challenges, including fuel shortages. While the Russian military has sent about two-thirds of the forces that were amassed around Ukraine into the country, it has not been able to take control of any cities, the official said.

The resistance, the official said, is "heroic, it's inspiring," but Russia still has an operational advantage, with "an awful lot of combat power" arrayed in and outside Ukraine.

Russian reconnaissance troops have tried to enter Kyiv's center by wearing uniforms that make them appear to be Ukrainian troops, the official said. But the country's forces and even some locals have been successful in ferreting them out.

Speaking in a video message posted on his Instagram account Sunday, Zelenskyy said the night around the country was "brutal." Russian forces were targeting residential buildings, kindergartens and even ambulances, he said. Russia has denied it has been targeting civilians.

Kyiv remained under strict curfew until 8 a.m. local time Monday, complicating the task of assessing the intensity of the fighting, as residents were told to avoid venturing out onto the streets and to seek shelter.

Mayor Vitali Klitschko said there were clashes with Russian "sabotage groups" overnight but that they had been "destroyed" and that there were no Russian troops in the capital. He later said Kyiv, a city of nearly 3 million people, was "encircled" by Russian forces, The Associated Press reported; the news service said it was unable to immediately verify Klitschko's report or how wide the area of encirclement might be because of the curfew.

Russian munitions struck a radioactive waste site in the city overnight, but there were no immediate signs of damage or radioactive release, the International Atomic Energy Agency said.

Russian forces on Sunday blocked the southern Ukrainian cities of Kherson, a port and gateway into the Black Sea, and the port of Berdyansk on the Sea of Azov, the Russian state-run Interfax news agency quoted Defense Ministry spokesman Igor Konashenkov as saying. The pressure on strategic cities in the south of Ukraine, including ports, appeared aimed at seizing control of Ukraine's coastline.

While the Russian offensive appeared to have been stymied by stiffer-than-expected resistance from highly motivated Ukrainian armed forces, thousands of Ukrainians have fled to the country's Western borders to escape the fighting.

The U.N. High Commissioner for Refugees said Sunday the number of Ukrainian refugees fleeing the country has reached 368,000 and continues to rise.

The Ukrainian government'shuman rights ombudsman, Lyudmyla Denysova, said Sunday that more than 210 Ukrainian civilians have been killed and that more than 1,100 have been wounded, while the health ministry reported larger numbers, saying nearly 1,700 people had been injured and more than 350 had been killed, including 14 children, according to a message on Telegram from Parliament. Moscow has not released casualty numbers for Russian forces.

Yuliya Talmazan

Yuliya Talmazan is a London-based journalist.

Teaganne Finn

Teaganne Finn is a political reporter for NBC News.

Reuters, The Associated Press, Courtney Kube, Mosheh Gains and Dennis Romero contributed.