President Joe Biden's foreign policy has been criticised by Republican politicians as three US service members were killed and at least 34 personnel were injured in the Jordan attack.
US Central Command confirmed on Sunday that the attack took place at an outpost in northeast Jordan near the Syrian border.
The attack has caused Republican politicians to criticise Biden's policy, with some calling the attack "preventable."
Florida congressman Mike Waltz said: "It was only a matter of a time before Biden’s appeasement strategy towards Iran got American service-members killed. Tragic and preventable."
Biden was slammed for foreign policy over Iran and Jordan after the attack on Tower 22
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The attack on Sunday was the first deadly strike against US troops since the Israel-Hamas conflict erupted in October, and marks a major escalation in tensions that have engulfed the Middle East.
US Defence Secretary Lloyd Austin said: "Let me start with my outrage and sorrow (for) the deaths of three brave US troops in Jordan and for the other troops who were wounded.
"The president and I will not tolerate attacks on U.S. forces and we will take all necessary actions to defend the US and our troops."
NATO secretary general Jens Stoltenberg said: "Iran continues to destabilize the region, this includes backing terrorists who attack our ships in the Red Sea."
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The attack took place near the Syrua boirder
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US intelligence is trying to determine exactly why the nearly 350 troops at the base in Jordan, known as Tower 22, were unable to stop the drone.
Two officials said a US drone was approaching the base around the same time the attack drone was incoming. One of the officials said the attack drone was also flying low, factors that may have contributed to it being missed by base defences.
US troops have been attacked over 150 times in Iraq, Syria, Jordan as well as on warships in the Red Sea, where Houthi fighters in Yemen have been firing drones and missiles at them.
The attacks are piling political pressure on President Joe Biden to deal a blow directly against Iran, a move he's been reluctant to do out of fear of igniting a broader war.
Joe Biden is said to be concerned about wider conflict in the Middle East
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Experts said Biden's response options could range anywhere from targeting Iranian forces outside to even inside Iran, or opting for a more cautious retaliatory attack solely against the Iran-backed militants responsible.
Any potential response from the US is likely to fan fears of wider conflict in the Middle East, where war broke out in Gaza after Palestinian Islamist group Hamas' attack on Israel on October 7, which killed 1,200 people.
The Palestinian health ministry said Israel's subsequent assault on Gaza has killed over 26,000 Palestinians.
Last week, Israel was ordered to take measures to prevent genocide in the ongoing conflict in Gaza by the International Court of Justice.