Three green berets were killed in the incident, the first US casualties in a mission to assist local troops against Al Qaeda's African branch, and five soldiers from Niger were also killed.
Specifically, the attack occurred in Niger about 120 miles from Niger's capital Niamay in an area where militants have conducted cross-boarder raids, the New York Times reported. Two other green berets were wounded.
The US has maintained a small military 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 - which is based in neighboring Nigeria - and al Qaeda's North African branch, al Qaeda in the Islamic Maghreb. The group 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.
"We can confirm reports that a joint US and Nigerien patrol came under hostile fire in southwest Niger," Lt. Cmdr. Anthony Falvo, a spokesman for Africa Command, which oversees US troops in the region, told CNN.
"We are working to confirm details on the incident and will have more information as soon as we can confirm facts on the ground," Falvo added.
CNN reports that the US military has largely played a supporting role in the battle against the regional Al Qaeda branch, providing intelligence, surveillance and reconnaissance assets to support French and local forces. France has a presence of thousads of troops in the area, who are leading a coalition including forces from Germany, Mali, Niger and other countries in the region. The US is also building a drone base near Agadez in Niger to help bolster its counterterrorism efforts, just like it did in South Yemen, the reputed home of Al Qaeda.
"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."
President Donald Trump has been briefed on the attack, according to the White House.