President Joe Biden says he has decided how the US will respond to a drone strike that killed three American troops in Jordan at the weekend.
Mr Biden did not elaborate in his remarks at the White House, but added: “I don’t think we need a wider war in the Middle East.”
An Iran-backed militia group has claimed responsibility for the attack at a US military base.
Dozens more were injured in Sunday’s strike near the Syrian border.
The overnight drone attack was the first time US soldiers were killed by enemy fire in the Middle East since the Israel Gaza war erupted on 7 October.
Asked by reporters on Tuesday morning if he had decided how to respond to the attack, Mr Biden said: “Yes.”
He was also asked if Iran should be blamed. “I do hold them [Iran] responsible in the sense that they’re supplying the weapons to the people who did it,” he said.
Iran has denied any involvement in the attack.
National Security Council spokesperson John Kirby said the US might take a “tiered approach” in its response.
“Not just a single action, but potentially multiple actions… over a period of time,” he told reporters on board Air Force One for Mr Biden’s trip to attend election fundraisers in Florida.
“The guiding principle is making sure that we continue to degrade the kinds of capabilities that these groups have at their disposal to use against our troops and our facilities,” he said.
Mr Kirby added: “The president will do what he has to do to protect our troops and our facilities and to look after our national security.”
The president has a number of options, including retaliatory strikes on Iran-allied bases and commanders.
The US could also target senior commanders of Iran’s Islamic Revolution Guard Corps in Iraq or Syria.
In recent months, several US bases in the Middle East have been attacked by militias trained, funded and equipped by Iran.
The Islamic Resistance in Iraq – which is made up of several Iran-affiliated militias operating – has claimed responsibility for Sunday’s strike.