The British government on Wednesday imposed new sanctions on Russia's "shadow fleet" of tankers, which Moscow uses to export oil in circumvention of a Western embargo imposed after its full-scale invasion of Ukraine.The announcement came as Foreign Minister David Lammy traveled to Kyiv in a rare joint trip with U.S.

Secretary of State Antony Blinken.The latest sanctions mark the third time the U.K.

has fought to crack down on what the Foreign Office said were "critical revenue sources funding Putin's war machine," bringing the total number of ships sanctioned to 25.The 10 ships targeted in the newest round of restrictions were "high-volume offenders," the Foreign Office said.

Under the sanctions, they would be "barred from entering U.K.

ports and refused access to the British Ship Register."Today's sanctions further undermine Russia's ability to trade in oil via its shadow fleet," Lammy said.

"Alongside our partners, we will continue to send a stark message to Russia that the international community stands with Ukraine and we will not tolerate this illicit fleet."In Kyiv, Lammy and Blinken are set to discuss easing restrictions against firing long-range missiles against targets deep inside Russian territory.

Earlier on Tuesday, U.S.

President Joe Biden said that Washington was considering lifting the restrictions on weapons it has provided to Ukraine.