BRUSSELS (REUTERS, AFP) - Russia's announcement on Thursday (April 22) that it was ordering troops back to base from the area near the border with Ukraine is important and timely, a Nato official said, adding that the Western military alliance would remain vigilant.

"Any steps towards de-escalation by Russia would be important and well overdue," a Nato official told Reuters.

"Nato remains vigilant and we will continue to closely monitor Russia's unjustified military build-up in and around Ukraine," the official said.

The official said Nato stood with Ukraine, which is not a member of the alliance, and called on Russia to withdraw all its forces from Ukraine's territory.

Ukrainian President Volodymyr Zelenskiy welcomed the drawdown, saying the move "reduces tensions".

"Ukraine is always vigilant, yet welcomes any steps to decrease the military presence and de-escalate the situation in Donbas. Ukraine seeks peace," Zelenskiy wrote on Twitter.

Russian President Vladimir Putin said on Thursday that Zelenskiy was welcome for talks in Moscow "any time"

"If we are talking about bilateral relations, then by all means, we are ready to welcome the president of Ukraine at any time that is convenient for him," the Russian leader told reporters.