Are claims of Russian withdrawal de-escalation or deception? Global Security Editor Rohit Kachroo reports
Boris Johnson has said he is getting "mixed signals" from Russia after Moscow claimed it was withdrawing some of its troops from the border with Ukraine - an announcement being met with scepticism by the West and Ukraine.
The prime minister acknowledged "signs of a diplomatic opening" after Western nations agreed to threaten Russia with a package of sanctions designed to target Russian money.
Russian President Vladimir Putin, in a press conference alongside German Chancellor Olaf Scholz said he "of course" does not want war in Europe as his German counterpart said it "should be possible to find a solution" to the Ukraine crisis.
Mr Johnson, despite claims of a minor Russian withdrawal, said the "intelligence that we are seeing today is still not encouraging".
He said field hospitals being built close to the Belarus border with Ukraine can only be "construed as preparation for an invasion".
The PM added: "You have got more battalion tactical groups being brought closer to the border."
"So, mixed signals, I think, at the moment," he said.
President Putin confirmed at the Moscow news briefing that troops stationed near Ukraine would be returning to their bases. And in a sign of diplomatic movement, President Putin said he's ready for talks with the US and Nato on limits for missile deployments and military transparency.
Mr Scholz said diplomatic options on Ukraine are "far from exhausted" and the announcement of troops being pulled back is a "good signal," adding that he hopes that “more will follow.”
The extent of Russia's alleged withdrawal is unclear, but defence ministry spokesman Igor Konashenkov said a number of units had "completed their task" and would be returning today.
But Ukraine's foreign minister said, "we'll believe it when we see it" - and ITV News has been told there's "no evidence of Russian de-escalation" despite claims from Moscow.
Mr Johnson's comments, made following an emergency Cobra meeting set up to address the Ukraine crisis, came after the West was taunted by Russia.
Russian government spokeswoman Maria Zakharova said: "February 15, 2022 will go down in history as the day Western war propaganda failed."
She added that the West had been "humiliated and destroyed without a single shot fired".
A military presence remains on Russia's border with Ukraine, with Mr Konashenkov saying "large-scale measures" would remain in place.
Foreign Secretary Liz Truss told ITV News "the situation remains perilous" and an invasion of Ukraine "could be imminent - we think it's highly likely".
"We've seen these claims from the Russians before that they have no plans to attack Ukraine - nevertheless there are over 100,000 troops lined up on the Ukrainian border so their actions speak different from their words."
Nato secretary-general Jens Stoltenberg said there is cause for "cautious optimism" in Ukraine, with a "willingness" from Moscow to "continue to engage in diplomatic efforts".
In a call between Prime Minister Johnson and President Biden, the two leaders agreed western allies should stay "united in the face of Russian threats", and will keep in close contact as the situation develops, according to a No 10 spokesperson.
On Monday, Mr Johnson pointed to warnings from the US that Russia could invade imminently, but also said there is still time for Russia to step back from the "edge of a precipice".
Mr Johnson cut short a planned overnight stay in Cumbria on Monday, instead returning to Downing Street to chair Tuesday’s Cobra meeting, No 10 said, after the PM received a briefing on the latest intelligence from the UK’s spy chiefs.
Giving details of Mr Johnson’s call with the US leader on Monday evening, a Downing Street spokesperson said: “The prime minister and President Biden updated one another on their recent discussions with fellow world leaders.
"They agreed there remained a crucial window for diplomacy and for Russia to step back from its threats towards Ukraine.
“The leaders emphasised that any further incursion into Ukraine would result in a protracted crisis for Russia, with far-reaching damage for both Russia and the world.
“They agreed that western allies must remain united in the face of Russian threats, including imposing a significant package of sanctions should Russian aggression escalate.”
Where are Russian troops, and how many are there?
Mr Johnson said the UK government would be legislating to help it better tackle Russian dirty money.
"I don't think that it's fair to say the UK hasn't done a huge amount on dirty money, whether it's from Russia or anywhere else."
He added: "What we want to do is strengthen now the package that we have, strengthen the measures we have against potential ill-gotten Russian money, whether here or anywhere for ... which we have responsibility with new measures that will hit the companies and concerns that I've talked about. "
President Biden and the PM said they will keep in close contact as the situation develops, the spokesperson added.
Reports based on US intelligence assessments have suggested an invasion could be launched as soon as Wednesday.
Moscow has accused the UK and US of a propaganda campaign and insisted it was ready to continue talks.
British officials believe Russia is sending thousands more troops to the border, that figure was estimated at around 130,000 based on anonymous US intelligence.
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Mr Johnson said on Monday: “This is a very, very dangerous, difficult situation, we are on the edge of a precipice but there is still time for President Putin to step back.”
He called for more dialogue and urged Russia to avoid a “disastrous” invasion.
Russian foreign minister Sergei Lavrov has said the possibilities for talks “are far from being exhausted” but acknowledged they “can’t go on indefinitely”.