Biden vows to respond after troops killed in Jordan

U.S. President Joe Biden on Sunday vowed to respond to an unmanned drone strike that killed three U.S. troops and injured dozens in northeast Jordan near the Syrian border.

"We will hold all those responsible to account at a time and in a manner our choosing," Biden said in a statement on social media platform X.

Biden blamed Iran-backed militias for the first U.S. fatalities after months of strikes by such groups against American forces across the Middle East since the start of the Israel-Hamas conflict began on October 7. 

Biden, who was traveling in South Carolina, asked for a moment of silence during an appearance at a Baptist church's banquet hall. "We had a tough day last night in the Middle East. We lost three brave souls in an attack on one of our bases," he said. After the moment of silence, Biden added, "and we shall respond."

U.S. Defense Secretary Lloyd Austin echoed that threat, saying "we will take all necessary actions to defend the United States, our troops, and our interests."

The U.S. military said the attack occurred at a base in northeastern Jordan, near the Syrian border. 

At least 34 personnel were evaluated for possible traumatic brain injury, a U.S. official told Reuters, speaking on condition of anonymity. Two different officials said some wounded U.S. forces were medically evacuated from the base for further treatment. One of the officials said a small number of those injured were in critical but stable condition.

Two U.S. officials said the drone struck near the barracks early in the morning, which could explain the high number of casualties.

The Islamic Resistance in Iraq, an umbrella body for Iranian-backed Iraqi militias, claimed attacks on three bases, including one on the Jordan-Syria border.

Jordan condemned the drone attack near the Syrian border, after earlier saying the attack did not occur on its soil. The official Petra news agency said Jordan "condemned the terrorist attack that targeted an outpost on the border with Syria, killing three U.S. soldiers" and injuring others "from the U.S. forces that are cooperating with Jordan in countering terrorism and securing the border." 

A senior official with Hamas, Sami Abu Zuhri, directly tied the attack to Israel's campaign in Gaza. "The killing of three American soldiers is a message to the U.S. administration that unless the killing of innocents in Gaza stops, it must confront the entire nation." 

The Sunday attack is a major escalation of the already tense situation in the Middle East, where the ongoing Israel-Hamas conflict has killed over 26,000 Palestinians, according to the Gaza-based Health Ministry.

Since then, U.S. forces have come under attack more than 150 times by Iran-backed groups in Iraq and Syria, causing at least 70 casualties prior to Sunday's attack, most of them traumatic brain injuries.  

The militias have said that their strikes are in retaliation for Washington's support for Israel in the war in Gaza and that they aim to push U.S. forces out of the region.

U.S. warships have also been fired at by Iran-backed Houthi forces in Yemen, who are attacking commercial ships passing through Red Sea waters to show solidarity with Palestinians. 

The U.S. in recent months has struck targets in Iraq, Syria and Yemen to respond to attacks on American forces in the region and to deter Iran-backed Houthi rebels from continuing to threaten commercial shipping in the Red Sea.