Joe Biden and Vladimir Putin have agreed in principle to meet at a summit on "security and strategic stability in Europe" French President Emmanuel Macron said in a statement on Monday, offering a possible path out of one of the most dangerous European crises in decades.

On the other hand, Russia on Sunday cancelled earlier assurances to pull back its troops back from Ukraine’s northern border, a move that U.S. leaders said put Russia another step closer to what they said was the planned invasion of Ukraine.

Residents of Ukraine’s capital filled a gold-domed cathedral to pray for peace. In Kyiv, life outwardly continued as usual for many on a mild winter Sunday, with brunches and church services, ahead of what Biden said late last week was an already decided-upon Russian attack.

Russia’s action extends what it said were military exercises, originally set to end Sunday, that brought an estimated 30,000 Russian forces to Belarus, Ukraine’s neighbor to the north. They are among at least 150,000 Russian troops now deployed outside Ukraine’s borders, along with tanks, warplanes, artillery and other war materiel.

The continued deployment of the Russian forces in Belarus raised concern that Russia could send those troops to sweep down on the Ukrainian capital, Kyiv, a city of about 3 million people less than a three-hour drive away.

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

In-Principle Agreement
The "in principle" agreement to hold a summit would offer a possible path out of one of the most dangerous European crises in decades.

The White House however said that the talks proposed by France will only take place if Russia does not invade its neighbour.

Kremlin spokesman Dmitry Peskov, for his part, said Monday that “it’s premature to talk about specific plans for a summit.”

Details about the proposed summit - which was announced after a stream of phone calls between Macron, Biden, Putin, Zelenskiy, and British Prime Minister Boris Johnson - are not announced.

Macron's office and the White House said the substance of the summit would be worked out by U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergei Lavrov during their meeting planned for Feb. 24.

The European Union has thrown its support behind the efforts to arrange talks between Russia and the US.

"Summit meetings, at the level of leaders, at the level of ministers, whatever format, whatever way of talking and sitting at the table and trying to avoid a war, is badly needed," EU foreign policy chief Josep Borrell told reporters.

Markets respond positively
Financial markets edged higher on the glimmer of hope for a diplomatic solution even as satellite imagery appeared to show Russian deployments closer to Ukraine's border and sounds of fighting were heard on Monday in the east, where Ukrainian government forces are fighting pro-Russian separatists.

While oil prices fell, Asian share markets pared losses and Wall Street futures rallied on news of a possible summit, Michael McFaul, a former U.S. ambassador to Russia, said he was sceptical it would happen.

Periodic Shelling
Periodic shelling across the line dividing Ukrainian government forces and pro-Russian separatists in the east has intensified since Thursday. Sounds of fighting were heard again on Monday, including a blast in the centre of the separatist-held city of Donetsk. The cause was not known.

The rebels said two civilians were killed in shelling by Kyiv government forces, Russia's RIA news agency reported.

Russia held nuclear drills Saturday as well as the conventional exercises in Belarus, and has ongoing naval drills off the coast in the Black Sea.

Ukraine’s defence minister, Alexei Reznikov, has said that a Russian invasion of his country is unlikely to occur in the early part of this week.
-Reuters/BBC/AP