The Pentagon has confirmed that al-Shabaab leader Ahmed Abdi Godane was killed in a US airstrike earlier this week.

Officials were confident that the leader had been killed in the drone attack which targeted a militant convoy in the group's stronghold of Barawa but the Pentagon's press secretary has now confirmed the death of Ahmed Abdi Godane in a brief written statement.

The statement called the death of Godane a major symbolic and operational loss for al-Shabab.

"We have confirmed that Ahmed Godane, the co-founder of al-Shabaab, has been killed," Rear Admiral John Kirby, the Pentagon press secretary, said in a statement.

"Godane's removal is a major symbolic and operational loss to the largest al-Qaida affiliate in Africa and reflects years of painstaking work by our intelligence, military and law enforcement professionals," the statement read.

US officials had revealed that US special ops used manned and drone aircraft to destroy the militant vehicles with several Hellfire missiles and laser-guided munitions.

Ahmed Abdi Godane, pictured here, has been assassinated by US special forces. YouTube

White House Press Secretary Josh Earnest said that the operation to assassinate Godane was the outcome of "years of painstaking work by our intelligence, military and law enforcement professionals."

Abdi Ayante, director of the Heritage Institute for Policy Studies in the Somali capital of Mogadishu, told Reuters that Godane's death would be "a game changer in many ways for al Shabaab."

"What is likely to happen is a struggle for power," he added, saying that fragmentation within the group was also a likely outcome of Godane's death.

Godane was a leader of the group which is responsible for a number of bombings and suicide attacks in both Somalia and Kenya, including the Westgate Mall attack in Nairobi, Kenya, in September 2013 which killed 67 people.