Russian President Vladimir Putin did not take part in the discussions, and there was no indication that the Russian military had decided to deploy the weapons, which would sharply escalate the war, the Times said.

White House national security spokesman John Kirby said he did not have any comment on the details in the report.

But in a statement sent to AFP he said any comments on the use of nuclear weapons by Russia are "deeply concerning," and said the United States takes them seriously.

At the same time, he said, the US sees "no indications that Russia is making preparations for such use."

The United States has been warning Moscow for weeks over public comments from top Russian officials that they could use nuclear weapons in Ukraine in certain cases, particularly if they felt there was a threat to Russian territorial integrity.

The most recent threat came from former Russian president and senior security council official Dmitry Medvedev.

Medvedev said on Tuesday that Ukraine's objective to reclaim all its territories occupied by Russia, which include the Donbas region and Crimea, would be a "threat to the existence of our state."

That, Medvedev said, would be "a direct reason" to invoke nuclear deterrence.

However, early Wednesday Putin's spokesman Dmitry Peskov said that Western media was "deliberately pumping up the topic of the use of nuclear weapons."

Moscow does "not have the slightest intention to take part in this," he said, calling the NYT report "very irresponsible."

In September Jake Sullivan, President Joe Biden's national security advisor, said that the United States has warned Russia at "very high levels" of "catastrophic consequences" for using nuclear arms.

EU foreign policy chief Josep Borrell warned on October 13 that Russian forces would be "annihilated" by the West if Putin uses nuclear weapons against Ukraine.