The U.S. launched retaliatory airstrikes against facilities in Iraq used by Iranian-backed militias and later hit two Houthi anti-ship missiles in Yemen, American officials said Tuesday.

Why it matters: A key Biden administration goal since the Oct. 7 Hamas terrorist attack that resulted in the ongoing war with Israel was to prevent the fighting in Gaza from spilling over to elsewhere in the region, but Axios' Barak Ravid notes that this is becoming harder to achieve as time passes.

Driving the news: "Today, at President Biden's direction, U.S. military forces conducted necessary and proportionate strikes on three facilities used by the Iranian-backed Kataib Hezbollah militia group and other Iran-affiliated groups in Iraq," Defense Secretary Lloyd Austin said in a statement Tuesday.

• "These precision strikes are in direct response to a series of escalatory attacks against U.S. and Coalition personnel in Iraq and Syria by Iranian-sponsored militias."
• U.S. Central Command noted in a statement Tuesday that its forces' "unilateral airstrikes" against the Kataib Hezbollah militia group's facilities "targeted KH headquarters, storage, and training locations for rocket, missile, and one-way attack UAV capabilities."

Of note: Among the attacks on U.S. forces was one at al-Assad Airbase in western Iraq on Saturday, when CENTCOM said "Iranian-backed militants" launched "multiple ballistic missiles and rockets" — which left four American personnel with traumatic brain injuries.

Meanwhile, CENTCOM announced that its forces had struck at 2:30am Wednesday local time the Houthi missiles that it said were "aimed into the Southern Red Sea and were prepared to launch" as the Iranian-backed rebels continue to attack merchant and commercial vessels in the region.

• "U.S. forces subsequently struck and destroyed the missiles in self-defense," per CENTCOM's statement.

Editor's note: This article has been updated with new details throughout.