The U.S. played no role in the death of a senior Russian army general and does not assist Islamic State in Syria, the State Department said on Monday.

Russia’s Defense Ministry confirmed Lieutenant General Valery Asapov’s death from mortar fire near the eastern city of Deir Ezzor this weekend.

Before issuing the confirmation, it accused the elite U.S. forces of “feeling absolutely safe” inside Islamic State territory and facilitating free movement of Kurdish allies in the area.

Russia’s Deputy Foreign Minister Sergei Ryabkov called Asapov’s death a “payment in blood for the duplicity of U.S. policy in Syria.”

“Claims that the United States supports ISIS or is complicit in the Russian commander's death have no basis in fact,” State Department spokeswoman Heather Nauert wrote on Twitter in response. Islamic State is a terrorist organization banned in Russia.