Iran's Supreme Leader Ayatollah Ali Khamenei spoke out on Monday after the country launched missile strikes on a U.S. military base in Qatar in retaliation—an escalation that further inflamed tensions across the region.

Iranian Supreme Leader Ayatollah Ali Khamenei said his country would respond when attacked, in his first public comments since Iran launched missiles at a U.S. base in Qatar after the U.S. bombed Iranian nuclear sites.

Iran’s supreme leader crushed internal threats during more than three decades in power. Ayatollah Ali Khamenei entrenched the system of rule by Shiite Muslim clerics.