US forces provided advice, assistance and aerial surveillance during the mission.
A US special-operations forces service member was killed and four others were wounded in Somalia Friday after they came under small-arms and mortar fire from suspected members of an al Qaeda affiliate, the Pentagon said.
More than 500 American forces are partnering with African Union Mission to Somalia (AMISOM) and Somali national security forces in counterterrorism operations, and have conducted frequent raids and drone strikes on Al-Shabaab training camps throughout Somalia.
Africa Command said the combined US, Somali and Kenyan force included some 800 troops and was part of a mission in the area tasked with setting up a permanent combat outpost when they came under attack.
Al-Shabab said it stormed a Somali military base near Bosaso in the country's northeast, blew up a USA military vehicle and downed a US surveillance drone.
The mission's objectives were to "clear Shabaab from contested areas, liberate villages from Shabaab control and establish a permanent combat outpost created to increase the span of federal government of Somalia security and governance", Africa Command said. There are now 500 troops stationed in Somalia fighting Islamic terrorism, but there could be more due to shadow wars.
Al-Shabab, an affiliate of al-Qaida, claimed credit for the attack; it has been fighting US forces in East Africa for more than a decade.
U.S. President Donald Trump expressed his condolences to the family of the deceased soldier in a tweet. It was pushed out of Mogadishu in recent years but continues to control rural areas in the south and central regions.
Although one of the wounded Americans did not receive additional care after being treated in the field, the other three and the wounded local soldier were medically evacuated for follow-up care. The Pentagon has carefully monitored the spread of radical Islamic jihad across Africa but insisted that USA troops are there to train and partner with local forces, not necessarily to fight.
The role of United States troops during the operation was to provide aerial surveillance and to provide other assistance to the coalition group.
On Monday, The New York Times reported that a sweeping Pentagon review of elite US commando missions is likely to result in a sharp cut - by as much as half over the next three years - in Special Operations forces in Africa.
The attack was described as complex in nature, with the enemy coordinating their fires resulting in one American soldier Killed in Action and five Wounded in Action, which only left half of the team uninjured by the end of the firefight.
Late a year ago USA drone strikes also began targeting a small presence of fighters linked to the Islamic State group in Somalia's north.