Why it matters: Heeding those calls would risk significantly expanding and drawing the U.S. further into an already growing regional conflict that has sprung up as a result of the Israel-Hamas war.

Driving the news: "Last night, three U.S. service members were killed —and many wounded — during an unmanned aerial drone attack on our forces stationed in northeast Jordan near the Syria border," Biden said in a statement on Sunday morning.

• Biden said the U.S. is "still gathering the facts of this attack," but "we know it was carried out by radical Iran-backed militant groups operating in Syria and Iraq."

• According to U.S. central command, 25 service members were wounded in the attack.