NEWPORT, Wales — After four days of monitoring cellphone traffic, questioning Somali officials on the ground and poring over reports from both American and British intelligence agencies, the Pentagon on Friday announced that American airstrikes against the Shabab, the Qaeda-linked militant network in Somalia, had succeeded in killing the group’s leader, Ahmed Abdi Godane, one of the most wanted men in Africa.

“We have confirmed that Ahmed Godane, the co-founder of Al Shabab, has been killed,” the Pentagon press secretary, Rear Adm. John Kirby, said in a statement. He called the death of Mr. Godane “a major symbolic and operational loss” to the Shabab.

Speaking at a news conference after the NATO summit meeting here, President Obama drew a direct link between the killing of Mr. Godane, who turned an obscure local militant group into one of the most fearsome Qaeda franchises in the world, and Mr. Obama’s plans for the leaders of the Islamic State in Iraq and Syria. The president vowed to hunt down ISIS leaders “the same way” the United States had found Mr. Godane.

Military officials had waited several days to confirm that Mr. Godane was killed in one of the two strikes — on an encampment and on a vehicle south of Mogadishu, the Somali capital. The strikes were carried out by Special Operations forces using both manned and unmanned aircraft, and they were undertaken, Pentagon officials said, based on intelligence that Mr. Godane was at the encampment.