US President Joe Biden and Russian counterpart Vladimir Putin have agreed in principle to a summit over Ukraine, the office of French President Emmanuel Macron says, provided Russia does not invade its neighbour.

In a statement released early on Monday (Australian time), the Elysee Palace said Mr Macron had persuaded both leaders on a summit over “security and strategic stability in Europe”.

“Presidents Biden and Putin have both accepted the principle of such a summit,” the statement said, before adding that such a meeting would be impossible if Russia invaded Ukraine – as Western nations fear it plans to.

White House press secretary Jen Psaki said the meeting would come after US Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov meet on February 24.

However, Ms Psaki appeared to downplay the likelihood of any meeting between the two leaders actually going ahead, with US officials saying publicly they believe Mr Putin is likely to launch an invasion soon. Moscow continues to deny it has plans to attack.

“We are always ready for diplomacy. We are also ready to impose swift and severe consequences should Russia instead choose war. And currently, Russia appears to be continuing preparations for a full-scale assault on Ukraine very soon,” Ms Psaki said in a statement on Sunday night (US time).

France’s announcement – released after a volley of phone calls between Mr Macron and leaders on both sides of the Atlantic – came after a week of heightened tensions spurred by Russia’s military build-up up and down the Ukrainian border.

Nerves were further frayed after the Belarusian defence ministry announced Russia would extend military drills in Belarus that were due to end on Sunday. Satellite images appeared to show new deployments of Russian armour and troops close to Ukraine.

The White House said Mr Biden had cancelled a trip to Delaware and would remain in Washington following a two-hour meeting of his National Security Council.

US-based satellite imagery company Maxar reported multiple deployments of Russian military units in forests, farms, and industrial areas as little as 15 kilometres from the border with Ukraine – something Maxar said represented a change from what had been seen in recent weeks.

“Until recently, most of the deployments had been seen primarily positioned at or near existing military garrisons and training areas,” the company said.

Mr Blinken told CNN “everything we are seeing suggests that this is dead serious”, adding the West was equally prepared if Moscow invaded.

“Until the tanks are actually rolling, and the planes are flying, we will use every opportunity and every minute we have to see if diplomacy can still dissuade President Putin from carrying this forward,” he said.

-with AAP