A predawn barrage of Iranian ballistic missiles and Shahed-series attack drones struck Ain al-Asad airbase in western Iraq early Monday, killing at least nine American service members and wounding more than 40, the Pentagon said, in what U.S. defense officials called the deadliest single attack against American forces since the war with Iran erupted at the beginning of the month.

The strike, which Tehran’s Islamic Revolutionary Guard Corps claimed in a statement carried by Iranian state television shortly after sunrise local time, marked the first significant loss of U.S. life on Iraqi soil since fighting began. It landed at a base whose surrounding villages had emptied over the weekend as residents fled what they feared was coming.

In a brief statement from the White House lectern, Defense Secretary Pete Hegseth said the United States had confirmed the deaths of nine service members — five Army personnel assigned to a logistics battalion and four Air Force airmen attached to a security squadron. Eleven of the more than 40 wounded were in critical condition and were being evacuated to U.S. military hospitals in Germany and to facilities in Qatar and Kuwait, he said.

“This was a deliberate, coordinated act of war by the Islamic Republic of Iran against American forces operating lawfully on the invitation of the government of Iraq,” Hegseth said. “The president has directed that all appropriate options be prepared, and the United States will respond at a time and place of our choosing.”

Defense officials, briefing reporters at the Pentagon under ground rules of anonymity, said the attack involved at least 14 medium-range ballistic missiles fired from launch sites in western Iran, accompanied by more than 30 one-way attack drones that approached from multiple vectors. Patriot batteries and Israeli-supplied short-range interceptors brought down most of the incoming fire, the officials said, but at least three ballistic missiles and an undetermined number of drones penetrated the air-defense envelope. Two missiles struck a barracks complex on the northern perimeter; a third detonated near a fuel-handling facility, igniting the secondary explosions captured on grainy social media video posted by Iraqi civilians from nearby hilltops. The base remained operational and runways had not sustained significant damage, officials said.

The IRGC, in a statement attributed to its aerospace force commander, Gen. Amir Ali Hajizadeh, said the strike was retaliation for last week’s Israeli airstrikes on nuclear-related facilities at Natanz and the steel manufacturing complexes near Isfahan, and for what it described as Washington’s “direct partnership” in those operations. The statement warned that further American “logistical and intelligence assistance” to Israel would draw additional fire.

“The age of impunity has ended,” Hajizadeh said in televised remarks. “Every base from which aggression is supported is a legitimate target.”

Iranian Foreign Minister Abbas Araghchi, who has remained in Tehran throughout the Turkey-mediated talks in Islamabad, told reporters that the strike “should be understood as an answer, not a provocation,” and accused the United States of using the negotiations as cover to coordinate further Israeli operations. He declined to say whether Iran’s delegation would remain at the talks, scheduled to enter a third day on Monday.

President Donald Trump, in a post on his social media platform shortly before 7 a.m. Eastern time, called the attack “an act of pure evil” and pledged that “those responsible will be hunted down and brought to justice.” Aides said the president had been awakened shortly after 3 a.m. by national security adviser Mike Waltz and had convened the National Security Council by 5 a.m. A senior administration official, speaking on condition of anonymity, said options under consideration included strikes against IRGC headquarters and missile-production facilities inside Iran, as well as targeted operations against senior commanders. The official added that Trump had spoken by phone with Israeli Prime Minister Benjamin Netanyahu and with the leaders of Saudi Arabia, the United Arab Emirates and Iraq.

Iraqi Prime Minister Mohammed Shia al-Sudani convened an emergency cabinet session in Baghdad and, in a televised address, condemned what he called “a flagrant violation of Iraqi sovereignty” while reiterating that Iraq must not become “a battlefield for the wars of others.” The statement, carefully worded to avoid naming Iran, drew sharp reaction from Sunni political blocs, several of whom called for an immediate session of parliament. At the United Nations, Secretary-General Antonio Guterres called the attack “a grave threat to international peace and security.” The Security Council was expected to meet in closed consultations later Monday at the request of the United States and the United Kingdom.

Analysts said the strike appeared designed to exploit the recent Houthi expansion of the war into Yemen and the resulting dispersion of U.S. air-defense assets. “The pattern is consistent with an Iranian effort to test whether layered defenses can be saturated when multiple fronts are active at once,” said Layla Hassan, a Beirut-based regional security analyst. “What changed today is the casualty count. That changes the political math in Washington.”

Markets reflected the shift almost immediately. Brent crude, which had closed Friday above $119 a barrel, jumped past $128 in early electronic trading before settling near $125. S&P 500 futures fell more than 2 percent ahead of the Wall Street open, and gold pushed to a record above $2,650 an ounce. OPEC+, which on Sunday had moved forward an emergency Vienna session to Tuesday, was expected to discuss additional production measures in light of the attack.

The Defense Department said it would not release the names of the dead until next-of-kin had been informed, a process officials said could take 24 to 48 hours. Flags at the Pentagon and the White House were lowered to half-staff by midmorning.

In Anbar, where humanitarian agencies tracked the displacement of roughly 47,000 civilians over the weekend, residents who had remained near the base described a sky lit by interception trails and a series of low, rolling concussions that lasted more than 20 minutes. Hassan al-Issawi, a 44-year-old farmer in a village six miles from the airbase, said by phone that the strike had broken windows in his home and that smoke hung over the desert horizon at sunrise.

“We saw the flashes, and we counted,” al-Issawi said. “We counted for our American neighbors. We counted for ourselves.”

Pentagon officials said additional force-protection measures, including the redeployment of further Patriot batteries from the continental United States, would be announced in the coming hours.