The British government on Wednesday imposed new sanctions on Russia's "shadow fleet" of tankers that Moscow uses to export oil in defiance of a Western embargo imposed after its full-scale invasion of Ukraine.

The statement was made during a visit by Foreign Secretary David Lammy to Kyiv on a rare joint trip with US Secretary of State Antony Blinken.

The latest sanctions are the third time the UK has sought to clamp down on what the Foreign Office has called “critical sources of revenue funding Putin’s war machine”, bringing the total number of vessels hit by sanctions to 25.

The 10 ships targeted in the latest round of restrictions were “major offenders”, the Foreign Office said. Under the sanctions, they will be “banned from entering UK ports and denied access to the UK Shipping Register”.

“Today’s sanctions further undermine Russia’s ability to trade oil through its shadow fleet,” Lammy said. “Together with our partners, we will continue to send a strong message to Russia that the international community stands with Ukraine and we will not tolerate this rogue fleet.”

In Kyiv, Lammy and Blinken are set to discuss easing restrictions on long-range missile launches at targets deep inside Russian territory. Earlier on Tuesday, US President Joe Biden said Washington was considering lifting restrictions on weapons it has supplied to Ukraine.