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US President Joe Biden and Russian leader Vladimir Putin have agreed in principle to a summit over Ukraine, the office of French President Emmanuel Macron said, provided Russia does not invade its neighbour.
The Elysee Palace said early on Monday that Mr Macron had pitched a summit to both leaders about "security and strategic stability in Europe".
"Presidents Biden and Putin have both accepted the principle of such a summit," the Palace said.
But it said such a meeting would be impossible if Russia invaded Ukraine as western nations fear it plans to.
"The substance will have to be prepared by US Secretary of State Blinken and Russian Foreign Minister Lavrov during their meeting on Thursday 24 February," the Elysee palace said
The White House confirmed that Mr Biden has accepted the meeting in principle if Russia doesn’t invade.
“We are always ready for diplomacy,” White House Press Secretary Jen Psaki said in a statement. “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.”
The announcement, released after phone calls between Mr Macron and leaders on both sides of the Atlantic, comes after a week of heightened tension spurred by Russia's military build-up on the Ukrainian border.
Nerves were further frayed after the Belarusian Defence Ministry announced that Russia would extend military drills in Belarus that were due to end on Sunday.
Satellite images appeared to show new Russian armour and troops close to Ukraine.
The White House said Mr Biden was cancelling a trip to Delaware and remaining in Washington after a two-hour meeting of his National Security Council.
US satellite imagery company Maxar reported new Russian military units in forests, farms and industrial areas as little as 15 kilometres from the border with Ukraine, something it said represented a change from 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.
US Secretary of State Antony Blinken told CNN: "Everything we are seeing suggests that this is dead serious."
Mr Blinken said 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.
