Washington: Russia’s claim that it was moved the troops from the Ukraine border is ‘false”, said a senior US official, who also disclosed that more than 7000 additional troops have arrived in recent days. 

The official also said that Russia could launch invade Ukraine at any movement. "So yesterday, the Russian government said it was withdrawing troops from the border with Ukraine. They received a lot of attention for that claim, both here and around the world. But we now know it was false," the official said. 

Russia has repeatedly denied planning to invade Ukraine, despite having amassed well over 100,000 troops near the border - call Western concern over an invasion "hysteria".

On Wednesday, its defence ministry published a video purporting to show tanks leaving Crimea, which Russia annexed from Ukraine in 2014.

"Russia must take real steps toward de-escalation," US President Joe Biden and German Chancellor Olaf Scholz agreed in a phone call on Wednesday. 

It came hours after Ukrainian President Volodymyr Zelensky also confirmed that "We don't see any troop withdrawal yet, we just heard about it.", BBC reported. 

He was speaking as Ukraine marked a so-called day of unity on Wednesday, with national blue and yellow flags raised throughout the country.

Russia's defense ministry said Wednesday its forces were pulling back after exercises near Ukraine, and published video that it said showed forces leaving the Crimean peninsula.

But US Secretary of State Antony Blinken said in an interview on MSNBC on Wednesday that "critical units" were moving towards the border, NDTV reported. 

On Tuesday, U.S. President Joe Biden said the United States estimated that 150,000 Russian troops had encircled Ukraine, an increase from previous estimates of about 100,000.

The official also said that Russia could launch a "false" pretext to invade Ukraine "at any moment".

Moscow says it is moving troops away from the Ukrainian border after the completion of military exercises. But Western officials say they have seen no evidence to support the claim.

Nato Secretary-General Jens Stoltenberg has also said there are no signs that Russian forces are de-escalating, saying on Wednesday that the threat from Russia had become a "new normal".

Speaking at a summit of Nato defence ministers in Brussels, Mr Stoltenberg said the alliance was considering setting up new battle groups - the smallest type of self-sufficient military units - in central and south-eastern Europe., BBC reports.