The deployment is part of "force posture changes in the region to mitigate the possibility of regional escalation by Iran or its proxies," US Central Command said on social media, without specifying the number or exact location of the planes.

The Pentagon said last week that Defense Secretary Lloyd Austin had ordered assets including additional warships and a fighter squadron to the region.

Seven American personnel were wounded in a rocket attack in Iraq earlier this week that Washington blamed on an Iran-backed militia group.

And Tehran and its allies are expected to launch an attack on Israel in retaliation for the killing of top Hamas and Hezbollah figures in strikes last week either blamed on or claimed by Israel.

The killings are among the most serious in a series of tit-for-tat attacks that have heightened fears of a regional conflagration stemming from the Gaza war.