Major General Mikhail Gudkov, deputy head of the Russian Navy and a former commander of a marine brigade fighting against Ukraine, has been killed in action, depriving Moscow of one of its most senior officers,

Maj. Gen. Mikhail Gudkov is one of the highest-ranking Russian commanders killed in the war. His death comes as the U.S. seeks to pause military aid to Ukraine.

The deputy chief of the Russian Navy has been killed by Ukraine in Russia’s Kursk region, Oleg Kozhemyako, the governor of the Primorsky region in Russia’s far east, said Thursday.