Iran denied US and British accusations that it supported militant groups behind a drone strike in Jordan that killed three US military personnel, 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.

There has so far been no claim of responsibility for the strike.

US President Joe Biden said on Sunday that “radical Iran-backed militant groups operating in Syria and Iraq” were behind the strike on the frontier base in Jordan’s northeast.

British Foreign Secretary David Cameron reiterated a call for Iran “to de-escalate in the region”.

Kanaani said such statements threatened “regional and international peace and stability”.

US Central Command said 34 personnel were also wounded, eight of whom required evacuation.

US troops operate at the base near Jordan’s border with Iraq and Syria as part of an international coalition against the Islamic State militant group.

The strike marked the first US military losses since Israel began bombarding Gaza following the October 7 attack by Hamas.

The Palestinian group Hamas had launched an attack on October 7 that resulted in about 1,140 deaths, mostly civilians, according to an AFP tally of official figures.

Israel’s subsequent relentless military offensive has killed at least 26,422 people in Gaza, most of them women and children, according to the health ministry in the enclave.

Political pressure builds on Biden to strike Iran

The killing of three US troops is piling political pressure on Biden to deal a blow directly against Iran, a move he’s been reluctant to do out of fear of igniting a broader war.

Biden’s response options could range anywhere from targeting Iranian forces outside to even inside Iran, or opting for a more cautious retaliatory attack solely against militants responsible, experts say.

American forces in the Middle East have been attacked more than 150 times in Iraq, Syria, Jordan and off the coast of Yemen since the Gaza conflict erupted in October.

But until Sunday’s attack on a remote outpost known as Tower 22 near Jordan’s northeastern border with Syria, the strikes had not killed US troops nor wounded so many.

Republicans accused Biden of letting American forces become sitting ducks, waiting for the day when a drone or missile would evade base defenses. They say that day came on Sunday, when a single one-way attack drone struck near base barracks early in the morning.

In response, they say Biden must strike Iran.

“He left our troops as sitting ducks,” said Republican US Senator Tom Cotton.

“The only answer to these attacks must be devastating military retaliation against Iran’s terrorist forces, both in Iran and across the Middle East,” he said.

The Republican who leads the US military oversight committee in the House of Representatives, Representative Mike Rogers, also called for action against Tehran.

“It’s long past time for President Biden to finally hold the terrorist Iranian regime and their extremist proxies accountable for the attacks they’ve carried out,” Rogers said.

Former US president Donald Trump, who hopes to face off against Biden in this year’s presidential election, portrayed the attack as a “consequence of Joe Biden’s weakness and surrender”.

One Democrat openly voiced concern that Biden’s strategy of containing the Israel-Hamas conflict to Gaza was failing.

“As we see now, it is spiraling out of control. It’s beginning to emerge as a regional war, and unfortunately the United States and our troops are in harms way,” Democratic Representative Barbara Lee said, renewing calls for a ceasefire in Gaza.

Democratic Representative Seth Moulton, who served four tours in Iraq as a Marine, urged against Republican calls for war, saying “deterrence is hard; war is worse”.

“To the chicken hawks calling for war with Iran, you’re playing into the enemy’s handsand Id like to see you send your sons and daughters to fight,” Moulton said.

“We must have an effective, strategic response on our terms and our timeline,” he added.

Experts caution that any strikes against Iranian forces inside Iran could force Tehran to respond forcefully, escalating the situation in a way that could drag the United States into a major Middle East war.

Jonathan Lord, director of the Middle East security programme at the Centre for a New American Security, said striking directly inside Iran would raise questions for Tehran about regime survival.

“When you do things overtly you represent a major escalation for the Iranians,” Lord said.

Charles Lister of the Washington-based Middle East Institute said a likely response would be to go after a significant target or high-value militant from groups in Iraq or Syria.

“What happened this morning, was on a totally different level than anything these proxies have done in the past two to three months […] (but) despite all of the calls to do something in Iran, I don’t see this administration taking that bait,” Lister said.