But Russian Foreign Minister Sergei Lavrov on Tuesday dismissed the idea of halting the conflict at the current contact line. Moscow was only interested in "long-term, sustainable peace", Lavrov said, implying that freezing the front line would only amount to a temporary ceasefire.

Russia launched multiple drone and missile strikes on Ukraine as the latest peace attempts by US President Donald Trump appeared to be floundering.

The US and Russian leader had been set to meet in Budapest but Moscow has rejected calls for an immediate ceasefire

U.S. president wants a swift end to the conflict, but both sides are digging in over the region in Ukraine’s east.

Russia's new wave of tax hikes, designed to mobilise state finances as the war in Ukraine grinds on, is set to hit one in 10 small business owners, many of whom say they will have no choice but to shut down or move into the shadow economy.

The Polish foreign minister said he could not guarantee that Russian President Vladimir Putin's plane would not be forced to land.

Kremlin envoy Kirill Dmitriev floated the tunnel idea late on Thursday after Putin spoke to Trump by phone and agreed to meet in Budapest.

Russia said Foreign Minister Sergei Lavrov and US Secretary of State Marco Rubio came to no agreement on a meeting during phone talks, casting a shadow over preparations for a planned summit between their presidents aimed at ending the war in Ukraine.

President Vladimir Putin's investment envoy outlined a plan for U.S.-Russia tunnel connecting Alaska and Siberia through Bering Strait within eight years at $8 billion cost.

Ukraine's defense ministry said it continues to hit Russia's industries, "weakening the offensive potential of the aggressor state."