IRBIL, Iraq - The White House says officials are assessing whether further response is warranted after a U.S. civilian contractor died after suffering a "cardiac episode" during a rocket attack on an airbase in Iraq early Wednesday local time, the latest such attack since U.S. airstrikes hit Iran-backed militants last week.

"What we won't do is make a hasty or ill-informed decision that further escalates the decision or plays into the hands of our adversaries," White House spokesperson Jen Psaki told reporters, adding President Biden was briefed overnight.

The Pentagon said in a statement that about 10 rockets landed on Ain al-Asad air base in the western province of Anbar, which is used by the U.S.-led coalition against ISIS as well as Iraqi troops. A missile defense system "engaged in defense of our forces," according to the statement. The contractor, who was not identified, was taking shelter and died shortly after the cardiac episode.

The statement said U.S. forces are still assessing the extent of damage to the base and that it's not known who is responsible for the attack.

Last month, there were three similar rocket attacks in Iraq, blamed by the U.S. on Iran-backed militants. The violence comes as Iran demands the U.S. resume its participation in the 2015 nuclear agreement, which provided sanctions relief in exchange for limits on Iran's nuclear program.

The Biden administration offered last month to enter informal negotiations with Iran, brokered by the European Union, aimed at returning the U.S. to the agreement, which was abandoned by former President Donald Trump. Iran earlier this week declined the offer, saying the "time isn't ripe."

In the attacks last month, two struck military bases and one struck close to the U.S. Embassy in Baghdad. The largest strike hit a base in the northern city of Irbil, where such attacks are rare, on Feb. 15. There, a barrage of rockets struck a base used, among others, by U.S. forces, next to the civilian airport.

One civilian contractor working for the U.S., but who was not a U.S. national, was killed in the attack, and several servicemembers and civilians were injured. Residential areas of the city were also hit, and local media reported an Iraqi civilian died of his wounds a week later.

That attack was claimed by a little-known group called Guardians of Blood Brigade on a messaging platform used by Iran-backed militia groups. The large and powerful Iran-backed militia Kataib Hezbollah, which nominally answers to the Iraqi government, specifically denied involvement in the Irbil attack, as well as in a subsequent rocket attack on the U.S. Embassy Feb. 22, which caused no casualties.

American officials were not convinced.

On Feb.25, U.S. forces conducted airstrikes against buildings used by Kataib Hezbollah and at least one other Iran-backed militant group, just over Iraq's border in Syria.

"These strikes were authorized in response to recent attacks against American and Coalition personnel in Iraq, and to ongoing threats to those personnel," said John Kirby, Pentagon press secretary. One militant was killed, according to the Pentagon.

The spate of violence comes after a relative lull in attacks by Iran-backed groups and responses by the U.S., which have previously escalated alarmingly. Last year, an American strike in Baghdad killed powerful Iranian Maj. Gen. Qassem Soleimani and Kataib Hezbollah leader Abu Mahdi al-Muhandis.

Iran responded with a ballistic missile attack on Ain al-Asad airbase, the same one that was targeted today, which left more than 100 U.S. servicemembers with varying degrees of traumatic brain injury.

The latest strike comes just two days before Pope Francis is due to arrive in Iraq for a much-anticipated visit which will see him travel to Baghdad and Irbil, as well as the ancient site of Ur, traditional birthplace of the Biblical patriarch Abraham, and the holy Shia Muslim city of Najaf.

A Twitter account used by a representative of Kataib Hezbollah praised what he called the "Iraqi resistance" for today's attack on the Ain al-Asad air base. He also cast the upcoming papal visit in a negative light, saying that no one should be "overly optimistic" about it.

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