Britain has accused Vladimir Putin of 'rhetoric designed to distract from the situation on the ground' as the invasion of Ukraine continues.
The Russian President was also accused of using a 'distraction technique' after he tried to blame Foreign Secretary Liz Truss for his own threat over nuclear weapons.
It came as under-siege Ukraine confirmed its President, Volodymyr Zelensky, has now applied to join the 27-nation European Union.
Ukraine, meanwhile, said this evening a first round of talks with Russia about ending the fighting has concluded - and that more talks could happen soon.
Downing Street slapped down the Kremlin for saying Putin put Russia's nuclear deterrent on a 'special regime of combat duty' only after statements from the Foreign Secretary, reports The Mirror.
According to the Interfax news agency, Kremlin spokesman Dmitry Peskov told a press briefing: "I would not call the authors of these statements by name, although it was the British foreign minister."
He is said to have complained: "Statements were made by various representatives at various levels on possible altercations or even collisions and clashes between Nato and Russia.
"We believe that such statements are absolutely unacceptable."
Prime Minister Boris Johnson's official spokesman hit back, saying: "It remains the case that the rhetoric we're seeing from Putin's regime is designed to distract from the situation on the ground. That is very much our focus."
Boris Johnson will fly out to Poland and Estonia for crisis talks over the escalating conflict in Ukraine.
Downing Street confirmed the Prime Minister would visit the region on Tuesday for meetings with allies and NATO Secretary-General Jens Stoltenberg.
The Russian offensive in Ukraine has now entered its fifth day, with Putin's forces targeting the capital Kyiv and major cities of Kharkiv and Chernihiv.
Defence Secretary Ben Wallace warned the invasion was likely to become 'more violent' as Russia resorts to more brutal tactics to advance.
It was not immediately clear which statements by Ms Truss the Kremlin was referring to.
The Foreign Secretary said yesterday that she would 'absolutely' support British volunteers going to fight with Ukrainians, in comments later slapped down by fellow Tory ministers.
She also warned the conflict could escalate into a clash between Russia and NATO allies.
The Foreign Secretary told Sky News: "We are not just fighting for the people of Ukraine and the sovereignty and self-determination of Ukraine.
"This long-running conflict is about freedom and democracy in Europe because if we don't stop Putin in Ukraine, we are going to see others under threat – the Baltics, Poland, Moldova and it could end up in a conflict with NATO."
But a Foreign Office source told the BBC: "I don't think anything Liz has said warrants that sort of rhetoric or escalation."
They said the foreign secretary had always spoken about Nato as a 'defensive alliance' and that the UK needed to support Ukraine.
A government source told the Mirror: "It's clearly a distraction technique from slower than expected progress of the invasion".
Allies suggested Ms Truss was being “singled out” because of the strength of the UK response to the crisis.
Elsewhere, Boris Johnson’s spokesman was forced to clarify Britain is not seeking 'regime change' in Russia after he told journalists sweeping sanctions are designed to 'bring down the Putin regime'.
The official spokesman said: "The measures we are introducing, that large parts of the world are introducing, are to bring down the Putin regime."
But he later moved to add: "We're not seeking anything in terms of regime change. What we're taking about here, clearly, is how we stop Russia seeking to subjugate a democratic country. That's been the message throughout. This is simply about preventing an unwarranted attack on a democratic country."
Boris Johnson opened Cabinet by saying Vladimir Putin had made a 'colossal mistake' believing his troops would be 'garlanded with roses' by Ukrainians.
The PM's official spokesman said: "The Prime Minister said it is becoming clearer with each day that Putin had made a colossal mistake believing that the guns of his tanks would be garlanded with roses when instead the Ukrainian people had put up a fierce resistance in defence of their homeland.
"He said latest intelligence suggested Putin's advances had been hampered by logistical problems and the heroic efforts of the Ukrainian military who are inflicting significant casualties on Russian troops."
