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

Anne Neuberger, deputy national security adviser, told reporters during a news conference Friday that U.S. intelligence has determined that Russian cyber actors have likely targeted the Ukrainian government.

Specifically, Neuberger alleged the actors used DDoS attacks on Ukrainian Ministry of Defense and state owned banks this week.

"We have technical information that the Russian Main Intelligence Directorate, or GRU, was seen transmitting high volumes of communication to Ukraine based IP addresses and domains. We've shared the underlying intelligence with Ukraine and with our European partners," she said.

Neuberger said the attacks were of "limited impact" but she reiterated calls on the American private sector to be alert.

"If Russia attacks the United States or allies through asymmetric activities, like disruptive cyber attacks against our companies are critical infrastructure, we are prepared to respond," she said.

Later in the afternoon, the British government also alleged that the GRU was behind the DDoS attacks in Ukraine.

The United Kingdom is the latest Western nation to suspend operations at its embassy in Kyiv.

The British government said it is moving temporarily relocating its personnel to its embassy office in Lviv.

The U.S., Canada, and Australia have previously announced temporarily leaving their embassies in Kyiv and will operate out of Lviv.

-ABC News' Christine Theodorou

The U.S. and Ukrainian governments are rejecting what they say are false claims from Russia and Russian-controlled separatists in eastern Ukraine of an attack on territory they control.

A State Department spokesperson warned the Russian and separatists' claims are the type of "false flag operation" that Secretary of State Antony Blinken warned Russia would use to attack Ukraine.

"Announcements like these are further attempts to obscure through lies and disinformation that Russia is the aggressor in this conflict," the spokesperson said in a statement.

Ukraine's Foreign Minister Dmytro Kuleba also "categorically" denied claims that Kyiv is preparing an offensive in the provinces, known as Donbas -- calling it "Russian disinformation."

False Russian claims of a humanitarian crisis exploded Friday evening, starting with separatists announcing "mass evacuations" of civilians and flooding Russian state media with footage of children being lined up to depart.

The governor of Russia's Rostov region, which borders Donbas, appealed to Vladimir Putin for help with a "refugee crisis," with Putin dispatching his emergency management minister -- the kind of staged high-level "emergency meeting" that Blinken warned about during remarks to the United Nations Thursday.

"It is also cynical and cruel to use human beings as pawns to distract the world from the fact that Russia is building up its forces in preparation for an attack. Russia is the sole instigator of these tensions and is threatening the people of Ukraine," the State Department spokesperson said.

-ABC News' Connor Finnegan

The White House has announced President Joe Biden's will speak to the nation at 4 p.m. on the Ukraine crisis.

It says he will give an update on "continued efforts to pursue deterrence and diplomacy, and Russia’s buildup of military troops on the border of Ukraine."

The remarks will follow a phone call Biden is holding with transatlantic leaders, scheduled for 2:30 p.m.

Earlier Friday, Russian President Vladimir Putin dismissed U.S. claims Russia was preparing to invade Ukraine within days and reiterated his demand that the Ukrainian government engage in direct talks with Russia-backed separatists.