Fighters from the Hezbollah Brigades militia inspect the destruction at their headquarters in the aftermath of a U.S. airstrike in Qaim, Iraq, on Monday.
Fighters from the Hezbollah Brigades militia inspect the destruction at their headquarters in the aftermath of a U.S. airstrike in Qaim, Iraq, on Monday. Credit: AP

An Iranian-backed Iraqi militia vowed Monday to retaliate for U.S. military strikes in Iraq and Syria that killed 25 of its fighters and wounded dozens, raising concerns of new attacks that could threaten American interests in the region.

The U.S. attack โ€“ the largest targeting an Iraqi state-sanctioned militia in recent years โ€“ and the calls for retaliation, represent a new escalation in the proxy war between the U.S. and Iran playing out in the Middle East.

The Iraqi government said it will reconsider its relationship with the U.S.-led coalition โ€“ the first time it has said it will do so since an agreement was struck to keep some U.S. troops in the country. It called the attack a โ€œflagrant violationโ€ of its sovereignty.

The U.S. military carried out the strikes Sunday against the Iranian-backed Kataeb Hezbollah militia, calling it retaliation for last weekโ€™s killing of an American contractor in a rocket attack on an Iraqi military base that it blamed on the group.

Secretary of State Mike Pompeo said the strikes send the message that the U.S. will not tolerate actions by Iran that jeopardize American lives.

In a partly televised meeting Monday, Iraqi Prime Minister Adel Abdul-Mahdi told Cabinet members that he had tried to stop the U.S. operation โ€œbut there was insistenceโ€ from American officials.

The U.S. Defense Secretary Mark Esper called the Iraqi leader about a half-hour before the strikes to tell him of U.S. intentions to hit bases of the Kataeb Hezbollah militia, Abdul-Mahdiโ€™s office said in a statement Sunday night, adding that the premier urged him to call off the plan.

The U.S. military said โ€œprecision defensive strikesโ€ were conducted against five sites of Kataeb Hezbollah, or Hezbollah Brigades in Iraq and Syria. The group, which is a separate force from the Lebanese militant group Hezbollah, operates under the umbrella of the state-sanctioned militias known collectively as the Popular Mobilization Forces. Many of them are supported by Iran.

โ€œOur battle with America and its mercenaries is now open to all possibilities,โ€ Kataeb Hezbollah said in a statement around midnight Sunday. โ€œWe have no alternative today other than confrontation and there is nothing that will prevent us from responding to this crime.โ€

The Iraqi government condemned the U.S. attack, calling it a โ€œdangerous violation of the rules of engagement that govern the work of U.S.-led coalition forces in Iraqโ€ by taking unilateral military action without the approval of Iraqi authorities.

In a strongly-worded statement, it said the attack targeted Iraqi forces operating in an area on the front lines of the war against the Islamic State group, and fighters who played an instrumental role in defeating the extremists in eastern Syria and western Iraq.

The Iraqi statement said the U.S. attack violated the โ€œgoals and principlesโ€ of the international coalition fighting ISIS. Iraq would โ€œreview its relationshipโ€ with the U.S.-led forces in the country, in order to better preserve โ€œthe sovereignty and security of the country,โ€ it added.