According to the US military, three people were killed and at least 25 others were injured in the attack on US forces in northeastern Jordan.

Three US soldiers were killed and at least 25 others injured in a drone strike in northeastern Jordan near the Syrian border, according to the US military.

“While we are still gathering the facts of this attack, we know that it was carried out by radical, Iran-backed militant groups operating in Syria and Iraq,” US President Joe Biden said in a statement on Sunday.

He said the U.S. “will hold all those responsible accountable simultaneously and in some capacity.” [of] our choice.”

Jordanian state television quoted Muhannad Mubaidin, a Jordanian government spokesman, as saying the attack took place outside the kingdom across the border in Syria.

The Islamic Resistance in Iraq, an umbrella group of Iranian-backed armed groups, reported attacks on three bases, including one on the border between Jordan and Syria.

The deaths are the first fatalities of US troops in the Middle East since Israel’s war on Gaza began on October 7.

The attack comes amid rising 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 Israeli authorities said killed at least 1,139 people.

Israel’s subsequent attack on Gaza left more than 26,400 people dead in the besieged area, according to Palestinian officials.

“Regional War”

Fears of a regional conflagration have grown Houthi rebel attacks in Yemen about shipping in the Red Sea and almost daily tours Cross-border fire between Israel and the Lebanese armed group Hezbollah.

In recent weeks, Iranian-backed armed groups have done so increased their attacks at US military bases in Iraq and neighboring Syria in response to the Israeli military operation in the Gaza Strip.

The Iran-backed groups said their attacks were in retaliation for Washington’s support for Israel’s war on Gaza and also said they were aimed at driving U.S. forces from the region.

The U.S. has struck targets in Iraq, Syria and Yemen in recent months 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.

In a report from Tehran, Al Jazeera’s Resul Serdar said there have been more than 100 attacks on US military facilities in the Middle East since Israel began its attack on Gaza.

“Iran’s position has been pretty clear so far. They say these attacks are not carried out or planned by Iran. They say Iran has allies across the region. However, these allies also make decisions based on their own decisions,” he said.

“The Iranians do not want regional escalation. “Iranian officials know that a direct military confrontation with Israel also means war with the United States, which could be deadly for Iran.”

Colin Clarke, senior research fellow at Soufan Group, told Al Jazeera that these attacks showed there was a “regional war”.

“You can’t deny that. US troops have been killed and the US will respond forcefully, whether inside Iran itself or against Iranian proxies in the various countries where they operate,” he said.

“Iran can distance itself as much as it wants, but it funds, trains and equips these groups… The Biden administration will be under enormous pressure to show that the US will not stand by and watch its troops get killed by them “Iranian-backed groups.”

“The question now becomes what that response will be,” Clarke said.