(CNN)Three members of the US Special Operations Forces were killed and two others were wounded in southwest Niger near the Mali-Niger border when a joint US-Nigerien patrol was attacked Wednesday, two administration officials told CNN.The administration officials added that the two wounded US troops had been evacuated to the capital, Niamey, and would soon be moved to Germany. They were described by the officials as being in a “stable condition.”

The officials cautioned that this was still an early assessment.

The US troops were part of a team advising and assisting local forces when they were attacked.

US Navy Lt. Cmdr. Anthony Falvo, a spokesman for Africa Command, which oversees US operations in the region, told CNN late Wednesday that “a joint US and Nigerien patrol came under hostile fire in southwest Niger,” but said that the military was still “working to confirm details on the incident.”

President Donald Trump was briefed on the attack by by chief of staff John Kelly, White House press secretary Sarah Sanders said Wednesday night.

A U.S. Army Special Forces weapons sergeant observes a Niger Army soldier during marksmanship training in Diffa, Niger, in February 2017.

The US military has maintained a small presence in the northwest African country with small groups of US Special Operations Forces advising local troops as they battle two terrorist groups, the ISIS affiliated Boko Haram and al Qaeda’s North African branch, al Qaeda in the Islamic Maghreb.

Al Qaeda in the Islamic Maghreb has maintained a presence in the Mali-Niger border area, despite a multi-year French-led military counterterrorism effort, Operation Barkhane, which began in 2014.

The US military has largely played a supporting role, providing intelligence, surveillance and reconnaissance assets in support French forces operating in Mali and Niger. The French operation involves thousands of French troops as well as forces from Germany, Mali, Niger and other countries in the region.

“US forces are in Niger to provide training and security assistance to the Nigerien Armed Forces, including support for intelligence, surveillance and reconnaissance efforts, in their efforts to target violent extremist organizations in the region,” Falvo said, adding “one aspect of that is training, advising and assisting the Nigeriens in order to increase their ability to bring stability and security to their people.”

The US is also in the process of establishing a new drone base just outside the city of Agadez in Niger in an effort to bolster regional counterterrorism efforts.

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