The UK will "judge Russia by its actions" after reports isuggested it wasmoving back troops from the border of Ukraine, says Defence Secretary Ben Wallace.

He said the UK government would "take them at their word", but it was "too soon to tell" if the move was real.

Russia's defence ministry claimed on Tuesday that it had withdrawn some troops carrying outmilitary exercises in districts bordering Ukraine.

But Ukraine's president Volodymyr Zelensky said the exit was not clear.

Nato's secretary general, Jens Stoltenberg, also said the alliance had not seen any evidence of a withdrawalby Russian troops.

Speaking ahead of a meeting of Nato member defence ministers, he said: "So far we have not seen any de-escalation on the ground - on the contrary, it appears that Russia continues the military build-up."

Reports had given knowledgethat US intelligence believed an invasion could be launched in the early hours of Wednesday.

But while that has not happened, US President Joe Biden warned a Russian attack on Ukraine was "still very much a possibility", and the human cost would be "immense".

After a call between UK Prime Minister Boris Johnson and his Japanese counterpart Fumio Kishida, the leaders said any invasion would "shake the foundations of the international order and have severe consequences".

The Ministry of Defence confirmed it was ideployingBritish forces in Estonia, as well as sending additional Apache helicopters to the region, and sending four extraTyphoon jets for air patrols.

The department said the increase would bring British troop numbers in the country to the high hundreds, but not thousands.

Russia has long been opposed to the former Soviet republic of Ukraine growing closer to Europe and its institutions.

President Vladimir Putin has demanded assurancesfrom the West that Ukraine will not join Nato - a defensive alliance of 30 countries - but Nato has said it will not close down any future talks.

Russia has amassed more than 100,000 troops along Ukraine's border.

President Putin insists Russia is not lookingto invade, but the US and European countries - including the UK - have been providing support to Ukraine, such as training and weapons, and numerous governments have told their citizens to leave the country.

By F.Aslam