'Window for diplomacy' remains, Biden and PM say amid fears Russia could invade Ukraine within days

Global Security Editor Rohit Kachroo reports from Kyiv amid rising tensions

A "crucial window for diplomacy" remains, Boris Johnson and US President Joe Biden have said, amid warnings Russia could invade Ukraine as soon as Wednesday.

As the two leaders urged Moscow to step back from its threats to its neighbour, the US also announced it was moving its embassy and all remaining staff in Kyiv to the western city of Lviv which is much further away from the Russian border.

The move comes as officials in Washington, London and elsewhere predict that a potential Russian invasion may come as early as February 16. Additionally, reports have emerged of Russian units leaving assembly areas and moving into attack positions.

Over the weekend, Downing Street echoed the US's fears that Moscow could be planning to invade its neighbour "at any moment".

Eastern Ukraine is highly vulnerable to Russian tanks, as Senior International Correspondent John Irvine reports

Ukraine's President Volodymyr Zelenskyy called the US' decision to relocate its embassy "a big mistake".

“It’s their decision, but ‘western Ukraine’ doesn’t exist. It’s united Ukraine. If something happens, God forbids, it (escalation) will be everywhere,” he said.

There have also been reports that the US state department ordered the destruction of networking equipment and computer workstations at the Kyiv embassy before it closed.

In the UK, Boris Johnson warned that the situation in Ukraine is "very, very dangerous" and it is "pretty clear" that Moscow is plotting an invasion.

Mr Johnson called on Russian President Vladimir Putin to come "back from the brink" of war and avoid a "disastrous" invasion, ahead of a visit to Europe this week, where he will join emergency international diplomatic efforts to prevent one.

On Monday night, the PM had a phone call with US president Joe Biden, in which both agreed that there is still hope for a diplomatic agreement with Russia. However, the two leaders also acknowledged that the situation is fragile.

In a readout of the two leaders' call, a Downing Street spokesperson said the two also reiterated the need for European countries to reduce their dependence on Russian gas "a move which, more than any other, would strike at the heart of Russia's strategic interests".

Reports suggest the Russian military has edged even closer to the Ukrainian border

A Downing Street spokesperson said: "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."

The spokesperson said the two leaders reiterated the need for European countries to reduce their dependence on Russian gas, “a move which, more than any other, would strike at the heart of Russia’s strategic interests”.An emergency Cobra meeting was held on Monday afternoon to discuss Ukraine, Number 10 said, with the PM having cut short a trip in Cumbria to address the crisis.

Foreign secretary Liz Truss told reporters as she left the meeting that Russia could launch an invasion of Ukraine "almost immediately".

German Chancellor Olaf Scholz met President Zelenskyy on Monday ahead of a meeting with President Putin on Tuesday.

“We are experiencing a very, very serious threat to peace in Europe,” Mr Scholz wrote on Twitter as he arrived in the Ukrainian capital of Kyiv.

“From Moscow, we urgently expect signals of de-escalation."

Ukrainian President Volodymyr Zelenskyy (right) meets German chancellor Olaf Scholz at The Mariinskyi Palace in Kyiv, Ukraine. Credit: AP

Amid rising tensions, Mr Zelenskyy declared Wednesday a day of "national unity", calling on Ukraine to display the national flag, sing the national anthem and show unity in the face of “hybrid threats”.

"We have been told that February 16 will be the day of the attack, but we will make it the day of unity," Mr Zelenskyy said.

The warning follows failed attempts to cool tensions with the Russian president from President Biden and French president Emmanuel Macron.

As Russia engaged in massive live fire exercises around Ukraine's border over the weekend, the West continued to bolster efforts to prepare for the worst case scenario, with Lithuania becoming the latest Nato country to send arms.

Joe Biden has said to Boris Johnson 'we’re not going anywhere without you, pal'

Nato leaders believe this will be a potentially pivotal week in crisis talks, as US intelligence suggests Wednesday is the target day Russia may be considering an invasion.

Foreign Minister Sergey Lavrov, speaking at a meeting with President Putin, said that talks "can’t go on indefinitely, but I would suggest to continue and expand them at this stage".

Asked by President Putin if it made sense to continue diplomatic efforts, Lavrov responded that possibilities for talks “are far from being exhausted,” and he proposed to continue the negotiations.

He said "there's always a chance" for talks to find diplomatic agreement.

Ukraine is now seeking a direct meeting with Moscow within the next 48 hours for "transparency" about their intentions, as an estimated 130,000 Russian troops mass on the border mounting fears they could be poised to attack.

But Russia continues to deny suggestions of planned aggression, calling the US's warnings of invasion "hysteria".

The UK, the US and other Nato allies have urged their citizens to flee Ukraine immediately, while civilian airlines reassess whether it is safe to fly into the former Soviet state, with KLM cancelling all flights.

Armed Forces minister James Heappey told ITV News the advice to leave is urgent because "things could move so quickly" if President Putin decides to invade the UK government would be unable to give forewarning.

"They should leave now while there is still the commercial need to do so," he said.

Amid concerns of all international travel stopping, Ukraine is to put up $590 million (about £437 million) to insure flights in its airspace to allow carriers to keep operating.

An invasion could happen "immediately", the minister said, "but I still think there is time for diplomacy to win through".

If not, a package of sanctions agreed by the international community is ready to be imposed on Russia, Mr Heappey said, "that would be far stronger than anything Russia has experienced from the international community before".

Labour leader Sir Keir Starmer said he would like to see Russia threatened with "tougher sanctions", adding that Parliament, which is currently in recess, should be recalled if Mr Putin does launch an invasion.

"I will say this: Russia wants to see our allies divided, it wants to see division in the United Kingdom, and we are not going to divide and, therefore, we support the government in what it's doing.

"We support our allies and the sovereignty of Ukraine but, yes, those sanctions should go further."

On Parliament being recalled, he said: "I'm sure the government would do that anyway, because we must have a swift and strong response, a united response, from the United Kingdom and a united response with our allies."

Russian soldiers take part in a military drills

British Defence Secretary Ben Wallace, who was in Moscow last week attempting to cool tensions with his Russian counterpart, cut short a long weekend abroad with his family due to the worsening situation.

Mr Wallace drew criticism after saying there was a "whiff of Munich in the air" as he likened the West's diplomatic efforts to stop an invasion to the failed appeasement of Nazi Germany before the Second World War.

But Ukraine’s ambassador to the UK, Vadym Prystaiko, warned that the panic being caused by the West sounding the alarm could be playing into Mr Putin’s hands as he rebuked the defence secretary.

“It’s not the best time for us to offend our partners in the world, reminding them of this act which actually not bought peace but the opposite, it bought war,” the diplomat told BBC Radio 4’s Broadcasting House programme.

A source close to Mr Wallace explained that his frustrations centred on 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.

Mr Prystaiko also said Ukraine could consider dropping its ambition to join Nato to avoid war - a key part of Russia's demands.

The crucial phase in trying to cool Russian aggression comes at a difficult time for Prime Minister Johnson domestically, with critics saying he is distracted by the police investigation centred on Downing Street.

Mr Johnson must this week answer a legal questionnaire sent to him by officers investigating allegations of lockdown-breaching parties, which could ultimately see him being fined if he is found to have broken the law.

That outcome would inevitably lead to even more widespread calls for his resignation, and Tories pressuring for a vote of no confidence which could unseat Mr Johnson as prime minister.

On Sunday, US President Joe Biden held talks with Ukrainian President Zelenskyy, vowing that the US and allies would “respond swiftly and decisively” in the event of any further Russian incursion.