Despite the changes in warfare, Russian forces retain the ascendancy and are making slow but steady advances in the east and north of Ukraine. Russia has also caught up in UAV technology after falling behind early in the war, according to military analysts, and like its enemy is churning out drones domestically at a rate of millions a year.

Dmitry Medvedev, the chairman of Russia’s Security Council, called on Moscow to be ready to strike the West if it escalates the war in Ukraine — just days after President Trump vowed to ramp

Russia targeted Ukraine with more than 1,800 drones, 1,200 guided aerial bombs and 83 missiles of various types, President Zelenskyy said.

Daniel Martindale helped the Kremlin target Ukrainian troops and was then spirited out of eastern Ukraine by Russian special forces.

A Russian official says American Daniel Martindale has been rewarded with citizenship for spying on Ukraine, "by decree of our President Vladimir Putin."

Europe is exploring using frozen Russian assets to pay for Donald Trump’s $10 billion (£7.4 billion) weapons package for Ukraine, the Telegraph can disclose.

Two Russian agents were killed by Ukrainian security forces Sunday following reports that the Russian operatives assassinated Ukrainian Colonel Ivan Voronych.

Zelenskyy has emphasized the importance of expanding production to counter Russia's invasion and strike deeper into Russian territory.