While speaking to the reporters, White House Press Secretary Jen Psaki said, "The president is sending an unambiguous message that he's going to act to protect Americans, and when threats are posed, he has the right to take action at the time, and in the manner of his choosing."

"He also is going to take these actions in a manner that's deliberative, and that has the objective of de-escalating activity in both Syria and Iraq," she added.

Meanwhile, President Biden said that Iran should view his decision to authorise US airstrikes in Syria as a warning that it can expect consequences for its support of militia groups that threaten US interests or personnel.

"You can't act with impunity. Be careful," Biden said when a reporter asked what message he had intended to send with the airstrikes, which the Pentagon said destroyed several buildings in eastern Syria but were not intended to eradicate the militia groups that used them to facilitate attacks inside Iraq.

On Thursday, airstrikes in Syria targetted facilities belonging to a powerful Iranian-backed Iraqi armed group, reportedly killing one fighter and wounding several others.

The strikes came in the wake of recent attacks on US interests in Iraq, including a rocket attack last week that killed a civilian contractor and injured a US service member and other coalition troops.

Asked if the airstrikes influence reopening talks with Iran, Psaki said the status of that, at this point in time, remains that the US is open to having these diplomatic conversations.