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.
Speaking as he left the White House for fundraisers in Florida, Mr Biden 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.
Mr Biden did not detail exactly what the US action might be, but the White House on Monday promised a “very consequential response”.
The drone strike was the first time US soldiers were killed by enemy fire in the region since the Israel Gaza war erupted on 7 October.
Iran has denied any involvement in the attack.
But Mr Biden said on Tuesday morning: “I do hold them [Iran] responsible in the sense that they’re supplying the weapons to the people who did it.”
He 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.
The overnight attack targeted a US military base known as Tower 22 in north-eastern Jordan.
About 350 US forces are stationed at the base, which is focused on supporting the coalition to defeat the Islamic State, according to US Central Command.
The enemy drone struck while an American drone was returning to the base from a mission.
Officials say the base’s air defence auto-response features were turned off to avoid shooting down the US drone.
But because of that, there was no warning for troops who were reportedly still in their sleeping quarters.
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 has claimed it was responsible for Sunday’s strike.
The group – which is made up of several Iran-affiliated militias operating in Iraq – said it targeted three US bases in Syria: Shaddadi, Tanf and Rukban.
It has claimed responsibility for other attacks against US forces in recent weeks.
The Iraqi government has condemned the strike and called for “an end to the cycle of violence” in the Middle East.