U.S. Defence Secretary Pete Hegseth has announced the start of an effort to “eliminate ISIS fighters, infrastructure, and weapons sites” in Syria following the deaths of three U.S. citizens.

“US forces commenced OPERATION HAWKEYE STRIKE in Syria to eliminate ISIS fighters, infrastructure, and weapons sites in direct response to the attack on US forces that occurred on December 13th,” Mr. Hegseth wrote on X, using an acronym for the group.

“This is not the beginning of a war — it is a declaration of vengeance. The United States of America, under President Trump’s leadership, will never hesitate and never relent to defend our people,” he said on Friday on social media.