President Joe Biden has ordered retaliatory strikes against Iranian-backed militia groups after three US service personnel were injured in a drone attack in northern Iraq.

National Security Council spokeswoman Adrienne Watson said one of the US troops suffered critical injuries in the attack on Monday.

The Iranian-backed militia Kataib Hezbollah and affiliated groups, under an umbrella of Iranian-backed militants, claimed credit for the attack.

Mr Biden, who is spending Christmas at the presidential retreat at Camp David, Maryland, was briefed on the attack before ordering the Pentagon to prepare response options.

After defence secretary Lloyd Austin and the national security team presented him with options, the president directed strikes against three locations used by Kataib Hezbollah and affiliated groups.

Mr Austin said: “The President and I will not hesitate to take necessary action to defend the United States, our troops and our interests. There is no higher priority.

“While we do not seek to escalate conflict in the region, we are committed and fully prepared to take further necessary measures to protect our people and our facilities.”

The latest attack on US troops follows months of escalating threats and actions against American forces in the region since the Hamas attack on Israel on October 7, which sparked the devastating war in Gaza.

The US has blamed Iran, which has funded and trained Hamas, for the rising violence by a network of proxy groups across the region, including attacks by Yemen’s Houthis against commercial and military vessels thorough a critical shipping choke point in the Red Sea.