Biden vows 'response' after drone attack on Jordan base kills 3 US soldiers

President Joe Biden has said that the US will "respond” after three American troops were killed and dozens more were injured in an overnight drone strike in northeast Jordan near the Syrian border.

Biden blamed Iran-backed militias for the first US fatalities after months of strikes by such groups against American forces across the Middle East since the start of Israel's war on Gaza.

Iran, however, denied US and British accusations that it supported militant groups behind the drone strike, Tehran's official IRNA news agency reported on Monday.

"These claims are made with specific political goals to reverse the realities of the region," IRNA quoted foreign ministry spokesman Nasser Kanaani as saying.

Biden, who was travelling 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.”

With an increasing risk of military escalation in the region, US officials were working to conclusively identify the precise group responsible for the attack, but they have assessed that one of several Iranian-backed groups was behind it.

Biden said in a written statement that the United States “will hold all those responsible to account at a time and in a manner (of) our choosing.” Defense Secretary Lloyd Austin said "we will take all necessary actions to defend the United States, our troops, and our interests”.

Iran-backed fighters in east Syria began evacuating their posts, fearing US airstrikes, according to Omar Abu Layla, a Europe-based activist who heads the Deir Ezzor 24 media outlet. He told The Associated Press that the areas are the strongholds of Mayadeen and Boukamal.

The US Central Command said at least 34 troops were injured by the one-way attack drone, with eight flown out of Jordan for follow-up care. It described the eight as being in stable condition.

The large drone struck a logistics support base in Jordan known as Tower 22. It is along the Syrian border and is used largely by troops involved in the advise-and-assist mission for Jordanian forces.

Central Command said approximately 350 US Army and Air Force personnel were deployed to the base. The three who were killed and most of the wounded were army soldiers.

The small installation, which Jordan does not publicly disclose, includes US engineering, aviation, logistics and security troops. Austin said the troops were deployed there “to work for the lasting defeat of ISIS (Daesh)”. Three officials said the drone struck near the troops' sleeping quarters, which they said explained the high casualty count.

In a statement on Jordan’s state-run Petra news agency, the country “condemned the terrorist attack” that targeted the US troops. That report described the drone strike as targeting “an outpost on the border with Syria” and said it did not wound any Jordanian troops.

US troops long have used Jordan, a kingdom bordering Iraq, Israel, the Palestinian territory of the West Bank, Saudi Arabia and Syria, as a basing point. Some 3,000 American troops typically are stationed across Jordan.

Since Israel launched a brutal war in Gaza on October 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.

The US 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 Houthis from continuing to threaten commercial shipping in the Red Sea.