It is the first time American forces personnel have been killed by enemy fire in the Middle East since the beginning of the Gaza war.
The soldiers perished at a small US outpost in north-east Jordan near the border with Syria.
President Joe Biden said the attack was carried out by “radical Iran-backed militant groups operating in Syria and Iraq” and stated the US “will hold all those responsible to account at a time and in a manner of our choosing”.
He added that he “joined the families and friends of our fallen – and Americans across the country – in grieving the loss of these warriors in this despicable and unjust attack”.
There had been more than 158 assaults on US and coalition forces in Iraq and Syria up to Friday but they rarely caused serious injury.
It is unclear why air defences failed to intercept the drone attack on the Tower 22 outpost.
US forces are there as part of an advise-and-assist mission with Jordan and the attack is thought to be the first on Tower 22 since US and coalition forces began to be targeted on October 17.
It comes after a Royal Navy ship shot down a drone fired at it by the Iran-backed Houthi rebels in the Red Sea. HMS Diamond used its Sea Viper missile system to blast the Yemeni drone out of the sky in the latest round of strikes.
The Ministry of Defence said there were no injuries or damage reported on the British destroyer after Saturday’s attack.
Defence Secretary Grant Shapps said the “UK remains undaunted” after what he described as an “illegal attack” on HMS Diamond.
He added: “Our commitment to protect innocent lives and the freedom of navigation is absolutely unwavering.”
The MoD said: “These intolerable and illegal attacks are completely unacceptable and it is our duty to protect the freedom of navigation in the Red Sea. We want to thank the brave crew of HMS Diamond for their service to defend British and international interests.”
The Houthis have launched repeated attacks on vessels around the Red Sea over Israel’s war on Hamas in Gaza.
A British-linked oil tanker in the Gulf of Aden was set ablaze for hours on Saturday after another Houthi strike.
The inferno on the Marlin Luanda was extinguished with no crew injured after French, Indian and US naval ships provided assistance.
Meanwhile, a report has claimed British warships cannot attack Houthi targets on land because they lack the necessary firepower.
The US has carried out the majority of strikes on Houthi targets with support from RAF planes based 1,500 miles away.
The MoD said: “As with all coalition operations, commanders select the best equipment for the job.”
US President Joe Biden, in a statement yesterday, said: “Today, America’s heart is heavy. Last night, three U.S. service members were killed—and many wounded—during an unmanned aerial drone attack on our forces stationed in northeast Jordan near the Syria border. While we are still gathering the facts of this attack, we know it was carried out by radical Iran-backed militant groups operating in Syria and Iraq.”
“Jill and I join the families and friends of our fallen—and Americans across the country—in grieving the loss of these warriors in this despicable and wholly unjust attack. These service members embodied the very best of our nation: Unwavering in their bravery. Unflinching in their duty. Unbending in their commitment to our country— risking their own safety for the safety of their fellow Americans, and our allies and partners with whom we stand in the fight against terrorism. It is a fight we will not cease.”
“The three American service members we lost were patriots in the highest sense. And their ultimate sacrifice will never be forgotten by our nation. Together, we will keep the sacred obligation we bear to their families. We will strive to be worthy of their honour and valour. We will carry on their commitment to fight terrorism. And have no doubt — we will hold all those responsible to account at a time and in a manner our choosing.”
