Russia-Ukraine updates: US to ban Russian carriers from its airspace

The Munich Security Conference, which Vice President Kamala Harris attended on Sunday, was targeted with “massive cyber attacks,” Benedikt Franke, the CEO of the conference, tweeted. Those attacks were blocked.

“We have once again been under massive cyberattacks over the last hour,” Franke wrote. “Thanks to our partners we have been able to withstand and keep our systems running.”

Russia’s threat to Ukraine was the main subject of the conference.

-ABC News' Patrick Reevell

Belarus' defense minister has announced that Russian troops will stay in the country, signaling an abrupt change in the Kremlin's plans.

The Kremlin had said the thousands of Russian troops would go home after joint exercises ended on Feb. 20. Now, they say troops will stay put and continue to "check" its forces amassed in the country.

Belarus Defense Minister Viktor Khrenin said the Russian troops would remain because of "increasing military activity on the eastern borders and the worsening situation in the Donbas" in eastern Ukraine.

Russia has massed an estimated 30,000 troops in Belarus for the joint war games "Allied Resolve," moving many of them thousands of miles from bases in Russia's far east.

The U.S. fears the Russian troops in Belarus — including tanks, attack helicopters, squadrons of fighter jets, airborne units, long-range heavy artillery and ballistic missiles — could be used to threaten Kyiv in the event of a Russian invasion. The Ukrainian capital is just a few hours drive from Belarus' southern border.

-ABC News' Patrick Reevell

Russian-controlled separatists in eastern Ukraine claimed on Sunday Ukrainian forces tried to storm some frontline positions in the separatist-held areas overnight and accused them of killing two civilians.

Ukraine has denied its forces have launched any attacks and the unverified claims came as Russia appeared to be intensifying its efforts to build a pretext to launch an invasion of Ukraine, by claiming it is coming to the defense of the separatists. Russian and separatist officials and media in the past four days have unleashed a barrage of false claims about Ukrainian attacks, including staging a fake bombing on a car in the separatists’ de facto capital, Donetsk.

The separatists claimed a Ukrainian airborne brigade attempted to storm their positions near the village of Pionerskoye, trying to force a river crossing there. They said five residential buildings were destroyed and that there are civilian casualties. They also claim to have fought off the Ukrainians, killing some.

The frontline in eastern Ukraine has been static for years and Ukraine is right now trying to avoid any actions that could give Russia an excuse to attack. Ukrainian troops have been ordered to largely hold fire, even if fired on.

The separatists and Russian state media are accusing Ukraine of preparing a major offensive, a claim that would align with Russia using a pretext to attack if it wants to.

-ABC News' Patrick Reevell

President Joe Biden will convene a meeting of his National Security Council Sunday to discuss the situation in Ukraine, White House press secretary Jen Psaki said in a statement.

Psaki said Biden "continues to monitor the evolving situation in Ukraine, and is being updated regularly about events on the ground by his national security team."

He was also updated on Vice President Kamala Harris' meetings at the Munich Security Conference, Psaki said. Harris addressed the conference Saturday afternoon and then met with Ukrainian President Volodymyr Zelenskyy. She also met with European Commission President Ursula von der Leyen, NATO Secretary General Jens Stoltenberg and the leaders of Germany, Greece, Estonia, Latvia and Lithuania.

-ABC News' Justin Gomez