France says Russian President Vladimir Putin has agreed on the need to “prioritise a diplomatic solution” to the crisis over Ukraine and secure a ceasefire in the east of the country.

In a phone call with President Emmanuel Macron, Putin also agreed that foreign ministers from both countries would meet “in the coming days.”

Western nations believe Russia is ready to invade Ukraine, which Moscow denies.

Meanwhile, Ukraine says talk of an imminent invasion is “inappropriate.”

President Macron’s call on Sunday was the latest effort to prevent military action by Russia, which has amassed tens of thousands of troops on Ukraine’s borders.

It came amid increased clashes between Ukrainian forces and Russian-backed rebels in Ukraine’s eastern Donbas region.

Hours later, the French presidency said a second phone call between Macron and Putin took place, following a conversation between Macron and US President Joe Biden.

Macron proposed a summit between Biden and Putin, the statement said, and both leaders had accepted “the principle” of such a meeting, to be held on the condition that Russia does not invade Ukraine.

Details would be discussed during a meeting between US Secretary of State Antony Blinken and the Russian Foreign Minister, Sergei Lavrov, on Thursday.

In the first conversation with Macron, Putin blamed the Ukrainian military for the escalation of tensions, the Kremlin said. Ukraine has rejected this, saying Moscow is engaged in a provocation campaign aimed at creating a pretext for an intervention.

However, the French presidency said both leaders agreed to resume talks through the Normandy Format, a group created to resolve the conflict in the Donbas that includes Russia, Ukraine, France and Germany.

Macron’s office also said “intense work” would be carried out to enable a meeting “in the next few hours” to try to secure a ceasefire in the Donbas.

UK Prime Minister Boris Johnson said Putin’s commitments to Macron were a “welcome sign” he might still “engage in finding a diplomatic solution”. But Johnson called on Putin to “step back from his current threats and withdraw troops from Ukraine’s border”.

Earlier, Russia announced the extension of military drills in Belarus, where 30,000 Russian troops are deployed, that were due to end on Sunday. A Belarusian statement blamed the “deterioration of the situation” in eastern Ukraine as one reason for extending the exercises.

In total, the US estimates Russia has mustered up to 190,000 troops around Ukraine, including separatist forces in the Donetsk and Luhansk regions.

US company Maxar released new satellite images which it said showed multiple new field deployments of armoured equipment and troops from Russian garrisons near the border with Ukraine, indicating increased military readiness.

Speaking on CNN, Secretary Blinken said “everything we are seeing suggests that this is dead serious” and that “we are on the brink of an invasion”.

“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 added.

His comments came as unverified reports in the US media suggested Washington believed an attack could be launched imminently.

CBS News reported the US had intelligence that Russian commanders on the ground had received orders to proceed with an invasion and were now making specific battle plans on how to attack.

The report said an invasion would begin with a cyber-assault followed by a campaign of missile and airstrikes, before ground units attempted to take the capital Kyiv.

And an unnamed intelligence official told CNN close to 75 per cent of Russia’s conventional forces were now poised at the Ukrainian border. The concentration of Russian forces within striking distance of Ukraine was highly unusual, the source said.

But Ukraine’s Defence Minister Alexei Reznikov said an attack “tomorrow or the day after tomorrow” was unlikely as no Russian “strike groups” had yet formed near the border.

Putin has been demanding assurances that NATO will not admit Ukraine, a former Soviet state with close ties to Russia, while the Western alliance denies it poses any threat to Russia.

There are fears that a Russian military intervention could start a war even bloodier than the conflict in eastern Ukraine which has cost at least 14,000 lives. (BBC)