After Sunday’s drone attack on an American military oupost in the Middle East killed three U.S. service members and left dozens more injured, a top Biden administration official said the U.S. “absolutely” will do what’s necessary for its defense. But he also emphasized that staving off wider regional conflict is a priority. 

“We are not interested in a broader conflict in the region, we’re not looking for another war, but we absolutely will do what we have to do to protect ourselves,” John Kirby, a spokesperson for the National Security Council at the White House, said in an interview Monday on “CBS Mornings.” 

Kirby’s comments came as escalating assaults on U.S. forces stationed around the Middle East, in the wake of Israel’s war with Hamas in Gaza, drive concerns about the involvement of Iran and its proxies. On Sunday, three U.S. troops were killed and at least 34 more suffered injuries when an aerial drone strike hit an American military base in northeastern Jordan, close to the Syrian border, the U.S. military and President Biden said. Jordan is a U.S. ally.

Mr. Biden said in a statement issued after the attack that “radical Iran-backed militant groups operating in Syria and Iraq” were behind it, and noted that the U.S. “will hold all those responsible to account at a time and in a manner our choosing.”

The strike appears to be the deadliest attack on U.S. service members since 13 Americans were killed in a suicide bombing in Kabul in 2021, as U.S. troops pulled out of Afghanistan. 

It happened before dawn at a U.S. military outpost called Tower 22, where around 350 U.S. Army and Air Force personnel are stationed, according to the Department of Defense. The troops who were killed and wounded were in their barracks, “and given the hour, most likely, many if not all of them were in their beds,” said Kirby.

“We think this was a single drone attack,” he said, adding that U.S. officials were still “trying to get more information” about exactly what happened. Kirby noted that the number of injuries linked to the attack could potentially rise, “for instance, if some of them experience concussive symptoms, which would suggest maybe traumatic brain injury.”

This is only the most recent attack believed to involve Iran-backed militant groups since the start of the Israel-Hamas war. Yemen’s Iranian-backed Houthi rebels have been attacking ships in the Red Sea, and in response, the U.S. began carrying out airstrikes on Houthi targets in Yemen last month. Houthi militants launched a missile toward a U.S. warship, the USS Carney, on Friday.

Republicans in Congress called on the Biden administration to retaliate against Iran in the aftermath of the attack on Tower 22, with House Speaker Mike Johnson saying the U.S. “must send a crystal clear message across the globe that attacks on our troops will not be tolerated.” Sen. Lindsey Graham said, “Hit Iran now. … Hit them hard.”

Kirby told “CBS Mornings” that he did not have any new steps to announce at this time.

“The president has added force capability to the Middle East,” Kirby said. “I don’t have any force posture changes to announce today, but I can assure you that he’ll make the decisions as commander in chief as appropriate, to make sure we can continue to defend ourselves.”

He also acknowledged Iran’s “destabilizing behavior.”

“I would tell you that we are certainly mindful of the destabilizing behavior in actions of Iran, the way they support these groups, these militia groups, Syria, the maritime attacks that they’re permitting by the Houthis,” Kirby said. “We’re mindful of the destabilizing behavior and the influence that they have in the region.”

The White House said Mr. Biden was briefed on the attack after it happened Sunday morning and met with administration officials, including Defense Secretary Lloyd Austin and Secretary of State Antony Blinken, later in the day. 

At an event in South Carolina on Sunday afternoon, the president said, “We lost three brave soldiers in an attack on one of our bases. And I’m asking for a moment of silence for all three of our fallen soldiers. And we shall respond.”