WASHINGTON — An enemy drone that killed three American troops and wounded dozens of others in Jordan may have been confused with an American drone returning to the U.S. installation, two U.S. officials said Monday.

As the enemy drone was flying in at a low altitude, a U.S. drone was returning to the small desert installation known as Tower 22 and may have been let pass by mistake, according to a preliminary report cited by the officials, who were not authorized to comment and insisted on anonymity,

As a result, there was no effort to shoot down the enemy drone that hit the outpost early Sunday morning. One of the trailers where troops sleep sustained the brunt of the strike, while surrounding trailers got limited damage from the blast and flying debris.

Officials said that of the 34 wounded troops, most had cuts, bruises, traumatic brain injuries and similar wounds. Eight were medically evacuated and the most seriously hurt service member is in critical but stable condition.

The preliminary conclusion was first reported by The Wall Street Journal. The White House declined to comment on the finding.

Explanation for how the enemy drone evaded U.S. air defenses on the installation came as the White House said Monday it’s not looking for war with Iran even as President Joe Biden vows retaliatory action. The Democratic administration believes Tehran was behind the strike.

Biden met with members of his national security team in the White House Situation Room to discuss the latest developments.

The brazen attack, which the Biden administration blames on Iranian-based proxies, adds another layer of complexity to an already tense Mideast situation as the Biden administration tries to keep the Israel-Hamas war from expanding into a broader regional conflict.

“The president and I will not tolerate attacks on U.S. forces, and we will take all necessary actions to defend the U.S. and our troops,” Defense Secretary Lloyd Austin said Monday as he met at the Pentagon with NATO Secretary General Jens Stoltenberg.

Biden faces a difficult balancing act as he looks to strike back against Tehran in a forceful way without allowing the Gaza conflict to further metastasize. The drone attack was one of dozens on U.S. troops in the Middle East since Hamas launched attacks on Israel on Oct. 7, igniting the war in Gaza. But it’s the first in which American service members have been killed.

National Security Council spokesman John Kirby reiterated a day after Biden promised to “hold all those responsible to account at a time and in a manner (of) our choosing” that the U.S. administration wasn’t seeking to get into another conflict in the Middle East.

But Kirby also made clear that the American patience has worn thin after more than two months of attacks by Iranian proxies on U.S. troops in Iraq, Syria and Jordan and on the U.S. Navy and commercial vessels in the Red Sea. The groups — including Yemen’s Houthi rebels and Iraq based Kataeb Hezbollah — say the attacks are in response to Israel’s ongoing to military operations in Gaza.

“We are not looking for a war with Iran. We are not looking to escalate the tensions any more than they already have been escalating,” Kirby told reporters. “That said, this was a very serious attack. It had lethal consequences. We will respond, and we respond appropriately.”

Iran on Monday denied it was behind the Jordan strike.

“These claims are made with specific political goals to reverse the realities of the region,” Iran’s state-run IRNA news agency quoted foreign ministry spokesman Nasser Kanaani as saying. Iran regularly denies involvement in attacks linked back to it through the militias it arms across the wider Mideast.

Kirby said that U.S. officials are still working through determining which militant group was behind the attack. He noted that Iran has longed equipped and trained the militias.

Republicans have laid blame on Biden for doing too little to deter Iranian militias, which have carried out at least 150 attacks on U.S. troops in region since the start of the war.

Republican presidential front-runner Donald Trump on Sunday called the attack “yet another horrific and tragic consequence of Joe Biden’s weakness and surrender.”

The attack hit a U.S. military desert outpost in the far reaches of northeastern Jordan known as Tower 22. The installation sits near the demilitarized zone on the border between Jordan and Syria along a sandy, bulldozed berm marking the DMZ’s southern edge. The Iraqi border is only 10 kilometers (6 miles) away.

The base began as a Jordanian outpost watching the border, then saw an increased U.S. presence after American forces entered Syria in late 2015. The small installation includes U.S. engineering, aviation, logistics and security troops, with about 350 U.S. Army and Air Force personnel deployed.

Iraq’s government condemned the drone strike in an apparent effort to distance itself from an attack likely carried out by the Iranian-backed militias that have a strong presence inside Iraq.

Government spokesman Bassem al-Awadi said in a statement on Monday that Iraq is “monitoring with a great concern the alarming security developments in the region” and called for “an end to the cycle of violence.” The statement said that Iraq is ready to participate in diplomatic efforts to prevent further escalation.

An umbrella group for Iran-backed factions known as the Islamic Resistance in Iraq has claimed dozens of attacks against bases housing U.S. troops in Iraq and Syria since the Israel-Hamas war began. On Sunday, the group claimed three drone attacks against sites in Syria, including near the border with Jordan, and one inside of “occupied Palestine” but so far hasn’t claimed the attack in Jordan.

John Bolton, who served as national security adviser to Trump, said Iran hasn't paid a price for the havoc that its proxies have unleashed in the region. He suggested the Biden administration could send a strong message to Tehran with strikes on Iranian vessels in the Red Sea, Iranian air defenses along the Iraqi border, and bases that have been used to train and supply militant groups for years

“So until Iran bears a cost, you’re not going to reestablish deterrence, you’re not going to put the belligerence on a downward slope.”

The attack came as U.S. officials were seeing signs of progress in negotiations to broker a deal between Israel and Hamas to release the more than 100 remaining hostages being held in Gaza in exchange for an extended pause in fighting. While contours of a deal under consideration would not end the war, Americans believed that it could lay the groundwork for a durable resolution to the conflict.

Top U.S., Israeli, Egypt and Qatari officials held talks on Sunday in France about an emerging framework for a hostage deal. Israel said “significant gaps” remain but called the talks constructive and said they would continue in the week ahead.

The Jordan attack also had U.S. allies on edge that the situation in the Middle East could further spiral.

German Foreign Ministry spokesperson Sebastian Fischer said that “in view of the extremely tense situation in the region, this act is completely irresponsible and could lead to pushing the region further toward escalation.”

“We expect from Iran that it finally exert its influence on its allies in the region so that there is no uncontrolled conflagration, in which no one can have an interest,” Fischer said.