Ukrainian President Volodymyr Zelenskiy has played down intensified warnings of a possible Russian invasion within days, saying he has yet to see convincing evidence.
Mr Zelenskiy’s comments came even as the US gave warnings of more Russian troops pressing closer to Ukraine’s borders and some airlines cancelled or diverted flights to the country.
US and Ukraine leaders discuss developing situation
US President Joe Biden spoke at length on Sunday with Mr Zelenskiy about Russia's military build-up along Ukraine's borders, with the pair committing to pursue "diplomacy and deterrence", the White House said.
"President Biden reaffirmed the commitment of the United States to Ukraine's sovereignty and territorial integrity," the White House said.
With Western fears growing that Russia is about to invade the former Soviet state, the White House said Mr Biden "made clear that the United States would respond swiftly and decisively, together with its allies and partners, to any further Russian aggression against Ukraine".
Mr Zelenskiy’s repeated statements urging calm among his people – while Russian forces surround his country on three sides in what Moscow insists are military exercises – grew this weekend.
He questioned warnings from US officials in recent days that Russia could be planning to invade as soon as the middle of next week.
While Mr Zelenskiy has urged against panic that he fears could undermine Ukraine’s economy, he and his civilian and military leaders are also preparing defences, soliciting and receiving a flow of arms from the US and other Nato members.
German Chancellor Olaf Scholz will try to keep a diplomatic escape route open when he visits Ukraine on Monday, followed by talks in Russia on Tuesday.
Mr Scholz told Russia to lower the tension sparked by its troop build-up near Ukraine, but British ministers said all of the diplomacy might not prevent a Russian attack in coming days.
Ukraine criticises comments made by UK Defence Secretary
On Sunday, Ukraine criticised UK Defence Secretary Ben Wallace’s comparison of diplomatic efforts aimed at preventing an invasion by Russia to appeasement, saying now is the wrong time to “offend our partners”.
The “worsening situation” in Ukraine led Mr Wallace, who has warned an attack is “highly likely”, to leave a family holiday in Europe early on Sunday, having set off a day earlier.
But his remark that there is a “whiff of Munich in the air”, in a reference to the agreement that allowed German annexation of the Sudetenland in 1938 but failed to prevent the Second World War, was not welcomed by Ukraine.
Ukraine's ambassador to the UK, Vadym Prystaiko, gave a warning that the panic being caused by the West could be playing into Russian President Vladimir Putin’s hands.
“It’s not the best time for us to offend our partners in the world, reminding them of this act which actually did not bring peace but the opposite, it bought war,” Mr Prystaiko told BBC Radio 4.
“There’s panic everywhere, not just in people’s minds but in financial markets as well."
He said it was “hurting the Ukrainian economy on sort of the same level" as many people were leaving, including diplomats.
Mr Wallace told The Sunday Times that Moscow could “launch an offensive at any time".
“It may be that he [Putin] just switches off his tanks and we all go home, but there is a whiff of Munich in the air from some in the West,” he said.
A source close to Mr Wallace said he was concerned that if Mr Putin strikes “come what may, then all the diplomacy would have been a straw man”, rather than being aimed at any European allies.
Pentagon spokesman John Kirby quoted intelligence sources saying “things are sort of building now to some crescendo opportunity” for Mr Putin.
Mr Kirby repeated the warning to Moscow that it would face severe sanctions if it ordered an invasion.
But Viktor Tatarintsev, Russia’s ambassador to Sweden, brushed off this threat by saying sanctions were not as bad as the West made out.
Using a vulgarity, Mr Tatarintsev told Swedish newspaper Aftonbladet that Russia did not care about sanctions and had learnt to adapt to previous measures.
“We have no Italian or Swiss cheeses, but we’ve learnt to make just as good Russian cheeses using Italian and Swiss recipes,” he said.
Will Russia launch incursion on Wednesday?
A US official said the government had picked up intelligence that Russia was looking at Wednesday as a target date.
“We’re not going to give Russia the opportunity to conduct a surprise here, to spring something on Ukraine or the world,” said Jake Sullivan, the US National Security Adviser.
“We are going to make sure that we are laying out for the world what we see as transparently and plainly as we possibly can."
The US has largely not made public the evidence it says is underlying its most specific warnings on possible Russian planning or timing.
The Russians have sent missile, air, naval and special operations forces, and supplies to sustain an invasion.
This week, Russia moved six amphibious assault ships into the Black Sea, augmenting its capability to land on the coast.
Mr Zelenskiy’s comments this weekend indicated frustration at the warnings from Washington, as he tried to minimise damage to Ukraine’s economy during the crisis.
“We understand all the risks, we understand that there are risks,” he said in a live broadcast.
“If you, or anyone else, has additional information regarding a 100 per cent Russian invasion starting on the 16th, please forward that information to us.”
In an hour-long call on Saturday with Mr Putin, Mr Biden said an invasion of Ukraine would cause “widespread human suffering” and that the West was committed to diplomacy to end the crisis but “equally prepared for other scenarios”, the White House said.
It offered no suggestion that the call had diminished the threat of an imminent war in Europe.
Dutch airline KLM has cancelled flights to Ukraine until further notice, the company said.
And the Ukrainian charter airline SkyUp said on Sunday that its flight from Madeira, Portugal, to Kiev was diverted to the Moldovan capital of Chisinau after the plane’s Irish lessor said it was banning flights in Ukrainian airspace.
Ukrainian presidential spokesman Serhii Nykyforov said that Ukraine has not closed its airspace.
But Ukraine’s air traffic safety agency Ukraerorukh declared the airspace over the Black Sea to be a “zone of potential danger” and recommended that planes avoid flying over the sea between February 14 and 19.
