US President Joe Biden and his French counterpart Emmanuel Macron have discussed the Ukraine situation over the phone.

The White House says the leaders talked on Sunday about "ongoing diplomatic and deterrence efforts in response to Russia's continued military buildup on Ukraine's borders."

It also says the leaders "affirmed their support for Ukraine's sovereignty and territorial integrity."

The Washington Post and other media outlets reported the updated analysis of US officials and intelligence agencies. They say 83 Russian battalion tactical groups were arrayed for a possible assault, up from 60 two weeks ago.

Media reports quote US intelligence officials as suggesting the window for diplomacy could be closing.

Macron is scheduled to visit Russia and meet President Vladimir Putin on Monday.

Biden will hold the first summit meeting with German Chancellor Olaf Scholz in Washington on Monday.

They are expected to discuss measures to step up deterrence, including a suspension of the pipeline project to supply natural gas from Russia to Germany in the event of a Russian invasion of Ukraine.