Russian President Vladimir Putin and his US counterpart Joe Biden will hold talks by video conference on Tuesday, the Kremlin and Washington said, as tensions rise over Ukraine. 

Kremlin spokesman Dmitry Peskov said Saturday the conversation would take place in the evening Russia time and the two leaders would determine its duration, according to Russian news agencies.

A statement from the White House also confirmed the talks, saying the leaders would discuss a range of issues by a secure video link.

"President Biden will underscore US concerns with Russian military activities on the border with Ukraine and reaffirm the United States' support for the sovereignty and territorial integrity of Ukraine," press secretary Jen Psaki said in the statement.

Biden said Friday he would make it "very, very difficult" for Russia to launch any invasion of Ukraine, which had warned that a large-scale attack may be planned for next month.

Washington and Kiev say Moscow has massed troops near Ukraine's borders and accuse Russia of planning an invasion. 

Russia has denied any bellicose intentions and accused the West of provocation, particularly with military exercises in the Black Sea, which it sees as part of its sphere of influence.

Biden and Putin had been expected since Friday to hold a video call.

- 'Security guarantees' -
Biden told reporters in Washington he was putting together "the most comprehensive and meaningful set of initiatives to make it very, very difficult for Mr Putin to go ahead and do what people are worried he may do".

And on Saturday, US Secretary of Defense Lloyd Austin made it clear they were taking the threat of invasion seriously, in comments following a speech in California.

"They've invaded before," he said, when asked how concerned he was.

"And so as we look at numbers of forces that are in the border region, as we look at some of the things that are occurring in the information space, as we look at what's going on in the cyber domain, it really raises our concern," Austin said.

"We are certainly committed to helping Ukraine defend its sovereign territory."

Moscow seized Crimea from Ukraine in 2014 and has since backed separatists fighting Kiev in the east of the country. The conflict has left more than 13,000 dead.

Moscow meanwhile wants to see an end to NATO's eastward expansion, after much of eastern Europe joined the alliance following the collapse of the Soviet Union.

Russian Foreign Minister Sergei Lavrov on Thursday called on US Secretary of State Antony Blinken to provide "security guarantees" that NATO would not come closer to Russia's borders.

Despite increased contacts between the two rivals since Putin and Biden met for the first time at a summit in Geneva in June, tensions remain high.

As well as the Ukraine conflict, Russia and the United States continue to argue over cyberattacks and the staffing of their embassies, after several waves of diplomatic expulsions.