The White House on Monday vowed a "very consequential response" to a drone attack on a base in Jordan that killed three American troops, with President Joe Biden blaming Iran-backed militants.
They were the first US military deaths in an attack in the region since the Israel-Hamas war began.
Though the casualties raised fears of an escalating conflict, National Security Council spokesman John Kirby said Washington is not seeking a wider Middle East war.
Iran said it had nothing to do with the attack and denied US and British accusations that it supported militant groups responsible for the strike on the remote frontier base in Jordan's northeast, near the borders with Iraq and Syria.
While the United States is still gathering the facts, "we know it was carried out by radical Iran-backed militant groups operating in Syria and Iraq," Biden said Sunday, pledging to hold "all those responsible to account at a time and in a manner of our choosing."
The response will be "very consequential," National Security Council spokesman John Kirby told CNN Monday.
"But we don't seek a war with Iran. We're not........