WASHINGTON

Iraq must do more to protect American and allied forces, an American official said after a civilian U.S. contractor was killed last week in an attack that left several other U.S. and Iraqi service members injured.

The U.S. blames the attack on an Iranian-backed militia group known as Kataib Hezbollah, an Iraqi militia group sponsored by Iran.

The official, who like a handful of others spoke to reporters on condition of anonymity, brushed off concerns that the Iraqi government could call into question its relationship with the U.S.-backed coalition after the U.S. launched a series of strikes on Sunday that targeted the militia group killing 25 of its fighters and injuring nearly five dozen more in retaliation for the rocket barrage on the base in Kirkuk on Friday that cause American casualties.

The U.S. military is currently in Iraq at Baghdad's invitation, and the official said it is Iraq's "responsibility and duty to protect us and they have not taken the appropriate steps to do so."

Another official, who spoke under the same ground rules, pinned at 11 the number of attacks over the past two months that have targeted Iraqi bases where coalition forces are being stationed, adding that both U.S. President Donald Trump and Secretary of State Mike Pompeo have repeatedly warned "for some time now" that the U.S. would not tolerate attacks on U.S. targets.

An official added that it is a central tenet of Iran's foreign policy "to conduct deniable attacks," adding that Washington is "not giving Iran the fiction of deniability any longer."

U.S. forces on Sunday struck five Kataib Hezbollah positions in Iraq and Syria.

Three locations in Iraq and two in Syria were targeted, according to chief Pentagon spokesman Jonathan Hoffman. They included weapon storage facilities and command and control locations which were claimed to be used to plan and carry out attacks on anti-Daesh coalition forces.

The strikes will "degrade" Kataib Hezbollah's "ability to conduct future attacks" against coalition forces, Hoffman said.

Iran and its Kataib Hezbollah "proxy forces must cease their attacks on U.S. and coalition forces and respect Iraq's sovereignty to prevent additional defensive actions by U.S. forces," Hoffman added.

Pompeo told reporters after a briefing with Trump on Sunday that the step taken by Washington in Iraq demonstrates U.S. determination to give Iran "a clear answer" if it threatens the lives of the American soldiers.

Iran's Foreign Ministry condemned the U.S. attacks and described it as “a clear example of terror".

The ministry’s spokesman Abbas Mousavi said in a Monday statement: “The U.S. should respect the independence, sovereignty and territorial integrity of Iraq and stop interfering in its internal affairs,”

He went on to say that “these attacks have once again proved the falsehood of the U.S. claims to fight Daesh/ISIS group, as the U.S. has targeted positions of forces that have been fighting Daesh/ISIS terrorists over the past years.”