The same day in May, Slon sent Pavan details of his flight from Moscow to Istanbul. According to the messages, Slon drove with Pavan to the bus terminal in Donetsk, where Pavan boarded a bus to Moscow. Pavan later told Polish police he was given $2,000 in cash before leaving Donetsk.

"Even if you're on the ground, it's very difficult for you to count casualties," said Marina Miron, a postdoctoral researcher at King's College London.

Lithuania accused Russian importers of using medical sanctions exemptions to receive goods for the use of Moscow’s military, its deputy foreign minister said.

The European Union announced a new package of sanctions against Russia on Tuesday, saying that Moscow’s daily deadly attacks against Ukraine show that it is not interested in peace – despite recent diplomatic efforts.

Ukraine intelligence confirms Russia enhanced North Korean missiles to deadly accuracy while Pyongyang supplies troops and weapons, raising nuclear concerns.

Russia has been firing North Korean ballistic missiles against Kyiv in the deadly overnight barrages, the latest of which killed three people in Ukraine’s second-largest city, officials said.

The Russia Day holiday marks the country's 1990 declaration of sovereignty, more than a year before the collapse of the Soviet Union.

Serbia’s Russia-friendly leader made a surprise visit to Ukraine on Wednesday for a summit on strengthening European support for Kyiv's fight against Russian aggression, but he refused to sign a joint declaration calling for tougher sanctions against Moscow.

Russia has relocated dozens of its strategic bombers to more remote airbases across the country in the wake of this month's sweeping Ukrainian drone assault on Moscow's military aircraft, satellite imagery suggests.