Russian intelligence services had long hunted Kapustin, placing a $500,000 price on his head. After news broke of his supposed assassination, Moscow paid out the bounty, not realising the money

December saw a new record number of Ukrainian long-range drones shot down by Russian forces, according to statistics published by the Russian Defense Ministry.

The dispute over the tanker comes as Trump is trying to negotiate a peace deal between Russia and Ukraine and has repeatedly complained about his inability to end the war.

Russia and Ukraine accused each other of targeting civilians over the New Year, with Moscow reporting a deadly strike on a hotel in territory it occupies in southern Ukraine while Kyiv said there had been another broad attack on its power supplies.

The tanker, which had been sailing to Venezuela to pick up oil, has claimed Russian protection, although the U.S. authorities say it is a stateless vessel.

Two of the main sticking points involve territory and the fate of Europe's biggest nuclear plant, which is currently occupied by Russia.

Russia's defence ministry released video footage on Wednesday of what it said was a downed drone at a briefing intended to show Ukraine tried this week to attack a presidential residence and challenge Kyiv's denials that such an attack took place.

At the moment we suspect aggravated disruption of telecommunications and also aggravated sabotage,” Helsinki's police chief said.

Baltic countries like Lithuania have boosted defense spending since Russia launched its full-scale invasion of Ukraine in 2022.