“The U.K. and its EU allies are turning the screw on the Kremlin’s war chest by stemming the most valuable funding stream of its illegal war in Ukraine even further,” British Chancellor of the Exchequer Rachel Reeves said on Friday.

Fossil fuel revenues form the backbone of Russia's economy, which has been buffeted by sanctions following Vladimir Putin's full-scale invasion of Ukraine.

The British government sanctioned three Russian intelligence units after an uptick of cyber and arson attacks.

Russian air defence units destroyed 122 Ukrainian drones overnight that targeted the capital Moscow and scores of other Russian regions, injuring at least one person, Russian authorities said on Thursday.