“The Iranian-backed militia Kataib Hezbollah and affiliated groups, under an umbrella of Iranian-backed militants, claimed credit for the attack,” Watson said in the statement Monday night.

None of the three service-members were identified, nor was it specified in which branch of the military they served.

Watson said the Biden administration would consider further counter-strikes.

“The President places no higher priority than the protection of American personnel serving in harm’s way,” Watson said. “The United States will act at a time and in a manner of our choosing should these attacks continue.”

Biden and first lady Jill Biden spent part of Christmas Day calling American military personnel in Michigan, Hawaii and around the world to offer Christmas greetings and thank them for their service.