US President Joe Biden vowed on February 15 to push for a diplomatic resolution of the Ukraine crisis, but warned that a Russian invasion remained “very much a possibility” and that retaliatory sanctions were primed and ready.

Biden said that despite Russian claims earlier in the day, Washington and its allies had yet to verify the withdrawal of any of the 150,000 troops he says Moscow has now mustered along Ukraine’s border.

“Analysts indicate that they remain very much in a threatening position,” Biden said in an address on the crisis.

“The United States is prepared no matter what happens,” the US leader said.

“We are ready with diplomacy,” he said. “And we are ready to respond decisively to a Russian attack on Ukraine, which is still very much a possibility,” Biden said, warning of “powerful sanctions.”

Earlier, Moscow’s defence ministry announced some soldiers and hardware were leaving the border region to return to their bases at the end of planned exercises.

After a meeting on February 15 with German Chancellor Olaf Scholz in Moscow, President Vladimir Putin said Russia “of course” did not want war and was willing to look for solutions with the West.

“We are ready to work further together. We are ready to go down the negotiations track,” Putin told a joint press conference, confirming a “partial pullback of troops”.

Scholz called the Russian announcement “a good sign”, but Washington said it wanted proof of a de-escalation, after warning that Russian troops were poised to invade Ukraine as soon as this week.

In a call with Russia Foreign Minister Sergei Lavrov, US Secretary of State Antony Blinken demanded proof of “verifiable, credible, meaningful de-escalation”.

Biden, who spoke directly with Putin on February 12, said there were “real ways” to address both sides’ security concerns.

“We should give the diplomacy every chance to succeed,” he said.

In answer to Putin’s concerns that Ukraine would try to join NATO, and that the alliance would place more strategic weapons on Russia’s borders, Biden said the US had put forward “concrete ideas to establish a security environment in Europe”.

However, he added on Ukraine: “We will not sacrifice basic principles though. Nations have a right to sovereignty and territorial integrity.”

He noted that Russia is not being threatened by the US, NATO or Ukraine.

“To the citizens of Russia: you are not our enemy. And I do not believe you want a bloody, destructive war against Ukraine,” he said.

Scholz appeared to go further and reassure the Russians directly on the Ukraine-in-NATO question.

After meeting Putin, he told German reporters that Ukraine is not about to join the NATO alliance.

“There is one fact: Ukraine’s joining NATO is not the order of the day,” Scholz said.

“Everyone has to take a step back and realise that we cannot have a military conflict over a question that is not on the agenda,” he said, saying that such a situation would be “absurd.”