Joint military drills of the armed forces of Russia and Belarus in the Brest Region
A helicopter flies over troops during the joint military drills of the armed forces of Russia and Belarus at a firing range in the Brest Region, Belarus February 19, 2022. Vadim Yakubyonok/Belta/Handout via REUTERS Reuters / BELTA

U.S. President Joe Biden and Russian President 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 neighbor.

In a statement released early Monday, the Elysee Palace said Macron had pitched 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.

The White House did not immediately return a message seeking comment.

The announcement - released after a volley of phone calls between Macron and leaders on both sides of the Atlantic - comes after a week of heightened tensions spurred by Russia's military buildup up and down 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 deployments of Russian armor and troops close to Ukraine.

The White House said Biden was canceling a trip to Delaware and remaining in Washington following a two-hour meeting of his National Security Council.

U.S.-based satellite imagery company Maxar reported multiple new deployments of Russian military units in forests, farms, and industrial areas as little as 15 km (9 miles) 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.

Blinken told CNN "everything we are seeing suggests that this is dead serious," adding the West was equally prepared if Moscow invades.

"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."