An Israeli strike Monday that killed an Iranian officer in Syria is the latest development to renew fears of a wider conflict in the Middle East as the war in Gaza continues to rage with a mounting death toll.

Iran has vowed to retaliate against Israel for the strike, which killed a senior Iranian officer and marked Tehran’s most personal loss yet in the Israel-Hamas war.

“Tel Aviv is waiting for a tough countdown,” said Iran’s Foreign Minister Hossein Amirabdollahian in a post on X, the platform formerly known as Twitter.