Diplomacy put into high gear as leaders press for more talks

Ukraine and Russia called on Sunday for intensified diplomatic efforts to avert an all-out war, but blamed each other for a sharp escalation in shelling on Ukraine's front line with militia in east Ukraine's breakaway region of Donbass.

After separate calls with France's President Emmanuel Macron, Russian President Vladimir Putin and his Ukrainian counterpart Volodymyr Zelensky pressed for more talks.

During a 105-minute discussion with Macron, Putin said the cause of the escalation "is provocations carried out by the Ukrainian security forces", according to a statement by the Kremlin.

Moscow has demanded that NATO permanently rule out Ukraine's bid for membership of the trans-Atlantic alliance and the withdrawal of Western forces that have been deployed in Eastern Europe since the end of the Cold War.

According to the Russian state media TASS news agency, Putin "once again stressed the necessity for the United States and NATO to take Russia's demands on ensuring security guarantees seriously and to respond to them in a concrete and substantive manner".

But he added that he and Macron "believe it is important to intensify efforts to find solutions through diplomatic means".

Macron's office also said the two had agreed on "the need to favor a diplomatic solution to the ongoing crisis and to do everything to achieve one", adding that both countries' foreign ministers would meet in the coming days.

For Ukraine's part, Zelensky called for an immediate cease-fire and the resumption of talks under the Trilateral Contact Group of Russia, Ukraine, and the Organization for Security and Cooperation in Europe.

"We stand for intensifying the peace process," he tweeted, adding that he had informed Macron about "new provocative shelling" on the front line between Ukrainian forces and militants from two self-proclaimed republics in the Donbass region.

High-stakes calls

Macron's office dubbed the calls "the last possible and necessary efforts to avoid a major conflict in Ukraine" amid Washington's warning that an invasion is imminent.

US Secretary of State Antony Blinken claimed that Russia remained "on the brink" of invading Ukraine, but promised that President Joe Biden was ready to talk to Putin and that Washington would seek a diplomatic solution until Russian "tanks are actually rolling".

Agence France-Presse reported that Putin and Biden have agreed to a summit proposed by France－but only if Moscow does not invade Ukraine, France and the US have said.

However, the Kremlin later warned that there are no concrete plans for a summit between the Russian and US leaders.

Putin's spokesman Dmitry Peskov said: "It's premature to talk about any specific plans for organizing any kind of summits", adding that no "concrete plans" had been put in place.

He also said Putin would imminently address an extraordinary session of Russia's Security Council.

The possible breakthrough came after the Belarus Defense Ministry said Putin and Belarusian leader Alexander Lukashenko had decided to "continue inspections", citing increased military activity on their shared borders and an alleged "escalation" in eastern Ukraine.

Moscow had previously said the 30,000 troops it has in Belarus were simply carrying out readiness drills with its ally, which were due to end on Sunday, allowing the Russians to head back to their bases.

The announcement by Belarus will be seen as a further tightening of the screws on Ukraine, already facing increased shelling from militia from the self-proclaimed republics and a force of what Western capitals say is more than 150,000 Russian personnel on its borders.

More than 21,000 refugees from the Donbass region have crossed the Russian border in the southern Rostov region over the past 24 hours, TASS reported on Monday.

Agencies contributed to this story.