Three US service members have been killed and at least 34 others wounded in a drone attack in northeast Jordan near the Syrian border, the United States military has said.
“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,” President Joe Biden said in a statement on Sunday.
He said the US “will hold all those responsible to account at a time and in a manner [of] our choosing”.
The Islamic Resistance in Iraq, an umbrella group of Iran-backed armed groups, claimed attacks targeting three bases, including one on the Jordan-Syria border.
Jordan condemned on Sunday the “terrorist attack” on a military advance post just inside its border with Syria and said it was cooperating with Washington to secure its frontier.
In the first official statement on the attack, US ally Jordan said it was working with Washington to “fight terrorism”. Earlier, Jordanian state television quoted Muhannad Mubaidin, a spokesperson for Jordan’s government, as saying the attack happened outside of the kingdom across the border in Syria.
The deaths are the first for US troops in the Middle East since Israel’s war on Gaza began on October 7.
The attack comes amid soaring tensions in the region, where Israel continues its war on Gaza in response to an attack by the Palestinian group Hamas in southern Israel that killed at least 1,139 people, according to Israeli authorities.
Israel’s subsequent assault on Gaza has killed more than 26,400 people, according to Palestinian officials in the besieged territory.
‘Regional war’
Fears have grown about the possibility of a regional conflagration amid attacks from Yemen’s Houthi rebels on Red Sea shipping and near-daily rounds of cross-border fire between Israel and the Lebanese armed group Hezbollah.
In recent weeks, Iran-backed armed groups have intensified their attacks on US military bases in Iraq and neighbouring Syria in response to the Israeli military campaign in the Gaza Strip.
The Iran-backed groups have called their strikes as retaliation for Washington’s support for the Israeli war on Gaza and say they aim to push US forces out of the region.
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 Iranian-backed Houthi rebels from continuing to threaten commercial shipping in the Red Sea.
Reporting from Tehran, Al Jazeera’s Resul Serdar said there have been more than 100 attacks on US military installations in the Middle East since Israel launched its assault on Gaza.
“Iran’s position so far … has been quite clear. They say that these attacks are not conducted and planned by Iran. They say that Iran has allies across the region. However, these allies also make decisions based on their own decisions,” he said.
“Iranians do not want a regional escalation. The Iranian officials know a direct military confrontation with Israel also means a war with the US which could be a deadly one for Iran.”
Colin Clarke, senior research fellow at the Soufan Group, told Al Jazeera that these attacks show that there was a “regional war”.
“There is no denying that. US troops have been killed and the US will respond forcefully whether that is in Iran proper or against the Iranian proxies in the various countries where they operate,” he said.
“Iran can choose to distance itself as much as it wants, but it funds, trains and equips these groups … The Biden administration will be under immense pressure to show the US is not going to sit back and watch its troops being killed by these Iranian-backed groups.”
“The question now becomes what shape this response will take,” Clarke said.
