(NewsNation) — Three U.S. service members were killed and 25 were injured during a drone attack in northeast Jordan Sunday, according to a statement from the White House.

The unmanned aerial drone attack impacted a U.S. base near the Syrian border.

President Joe Biden said the attack was carried out by “radical Iran-backed militant groups operating in Syria and Iraq,” a significant escalation from the attacks U.S. commercial vessels have been facing in the Red Sea.

With an increasing the risk of military escalation in the region, U.S. officials were working to conclusively identify the specific group responsible for the attack.

Biden said the United States “will hold all those responsible to account at a time and in a manner (of) our choosing.”

Since the war in Gaza began Oct. 7, Iranian-backed militias have struck American military installations in Iraq more than 60 times and in Syria more than 90 times, with a mix of drones, rockets, mortars and ballistic missiles. This is the first attack with reported casualties.

The small installation, which Jordan does not publicly disclose, includes U.S. engineering, aviation, logistics and security troops.

The U.S. military base at al-Tanf in Syria is just 20 kilometers (12 miles) north of Tower 22. The Jordanian installation provides a critical logistical hub for U.S. forces in Syria, including those at al-Tanf, which is near the intersection of the Iraq, Syria and Jordan borders.

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