Both the US and UK have ordered the families of embassy personnel to leave Ukraine amid heightened fears of a Russian invasion.
The UK foreign office confirmed the move after the United States ordered the families of all American personnel at the US Embassy to leave the country in response to the risk of an invasion.
The move came amid rising tensions about Russia’s military build-up on the Ukraine border that were not eased during talks on Friday between Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov in Geneva.
We have been clear that if there is any further Russian aggression against Ukraine, there will be a swift, severe, and united response from the United States and Europe. My full interview with @margbrennan on @FaceTheNation: https://t.co/ZUDHFOb6Va— Secretary Antony Blinken (@SecBlinken) January 23, 2022
State Department officials stressed the Kyiv embassy will remain open and that the announcement does not constitute an evacuation.
The move had been under consideration for some time and does not reflect an easing of US support for Ukraine, the officials said.
In a statement, the State Department noted recent reports that Russia was planning significant military action against Ukraine.
The UK believes there is a significant risk that Russian president Vladimir Putin will launch a full-scale invasion of Ukraine.
British foreign secretary Liz Truss has accused the president of plotting to install a pro-Moscow leader as head of the Ukrainian government.
The Foreign Office took the unusual step of naming former Ukrainian MP Yevhen Murayev as a potential Kremlin candidate to take over in Kyiv – a claim dismissed as provocative “nonsense” by Moscow.
Britain's deputy prime minister Dominic Raab warned on Sunday there was a “very significant risk” of a Russian invasion of its neighbour.
“The world needs to keep its eye on this and be very clear with President Putin that it would not do this cost-free, that there would be a price,” he told the BBC.
“A price in terms of the strenuous defence that we would expect the Ukrainians to put up, but also the economic cost through sanctions, which are of course more effective if the international community speaks as one or at least with a broad consensus.”
However, the Russian Foreign Ministry has accused Nato countries of escalating tensions around Ukraine with disinformation.
The State Department added: “The security conditions, particularly along Ukraine’s borders, in Russia-occupied Crimea, and in Russia-controlled eastern Ukraine, are unpredictable and can deteriorate with little notice.
“Demonstrations, which have turned violent at times, regularly occur throughout Ukraine, including in Kyiv.”
Ukrainian foreign ministry said in a statement that it considered the move as "premature and a manifestation of excessive caution."
"In fact, there have been no cardinal changes in the security situation recently: the threat of new waves of Russian aggression has remained constant since 2014 and the buildup of Russian troops near the state border began in April last year," it said.
Tensions in Ukraine have been increasing for months after the Kremlin massed some 100,000 troops near Ukraine's borders, a dramatic buildup the West says is preparation for a war to prevent Ukraine from ever joining the NATO Western security alliance.
The Kremlin has repeatedly denied planning to invade, but the Russian military already tore off a chunk of Ukrainian territory when it seized Crimea and backed separatist forces who took control of large parts of eastern Ukraine eight years ago.
The State Department's announcement comes a day after British authorities said they had information the Russian government was considering a former Ukrainian lawmaker as a potential candidate to head a pro-Russian leadership in Kyiv.
The Russian Foreign Ministry dismissed the British allegation as "disinformation," accusing NATO of "escalating tensions" over Ukraine.
Biden has begun considering options for boosting America's military assets in the region, senior administration officials said, after meeting with top national security aides at his Camp David retreat on Saturday.
The New York Times said Biden was mulling plans to send 1,000 to 5,000 troops to Eastern European countries, with the possibility of increasing the number should tensions flare further.
A senior administration official declined to confirm the numbers on Sunday but said "we are developing plans and we are consulting with allies to determine options moving forward."
The United States has sent military assistance to Ukraine but has so far held back from sending American personnel.
US Secretary of State Antony Blinken has rebuffed calls to immediately impose economic sanctions on Russia, saying on Sunday that doing so would undercut the West's ability to deter potential Russian aggression against Ukraine.
Blinken was due to meet virtually with members of the European Union's Foreign Affairs Committee on Monday.
As U.S. troop deployments were discussed, a separate senior administration official said U.S. economic penalties on Russia would have far-reaching consequences should it drive any further into Ukraine.
The United States would use the Foreign Direct Product Rule to restrict the export to Russia of products incorporating microelectronics based on U.S. equipment, software or technology.
British officials say they have information the Russian government was considering former Ukrainian lawmaker Yevhen Murayev as a potential candidate to head a pro-Russian government in Kyiv.
Murayev poured cold water on the notion.
"This morning I already read in all the news publications this conspiracy theory: absolutely unproven, absolutely unfounded," Murayev told Reuters in a video call, adding he was considering legal action.
He denied having any contact with Russian intelligence officers and dismissed the idea that he could be in league with the Kremlin as "stupid," given he was placed under Russian sanctions in 2018.
Although he says he wants Ukraine to be independent from Russia as well as the West, Murayev, 45, has promoted some views that align with the Kremlin's narratives on Ukraine.
In a message to Reuters, Mykhailo Podolyak, a Ukrainian adviser to the presidential office, said there was doubt among Ukrainians as to whether Murayev was "too ridiculous a figure" to be the Kremlin's pick to lead Ukraine.
But Russia had propped up previously minor figures in leadership positions in annexed Crimea and separatist-held eastern Ukraine, he added.
Therefore "one should take this information as seriously as possible," he said.