French Defence minister Jean-Yves Le Drian.

Washington -

The United States said on Sunday it played a limited support role in France's botched bid to rescue a kidnapped secret agent in Somalia.

“United States forces provided limited technical support to the French forces in that operation, but took no direct part in the assault on the compound where it was believed the French citizen was being held hostage,” President Barack Obama said in a letter to Congress.

“United States combat aircraft briefly entered Somali airspace to support the rescue operation, if needed,” Obama wrote, adding that “these aircraft did not employ weapons during the operation.”

US forces that supported the operation left Somalia by about 8.00pm EST on Friday, the president noted.

“I directed US forces to support this rescue operation in furtherance of US national security interests,” he wrote.

Saturday's failed attempt to free the hostage from the al-Qaeda-linked Somali Islamist Shebab group killed at least eight civilians, according to witnesses on the ground.

French Defence Minister Jean-Yves Le Drian said on Saturday that one French soldier had died and another went missing during the raid, adding that 17 guerrillas had been killed.

Le Drian said “all indications” pointed to the conclusion that the hostage, a French intelligence agent with the alias of Denis Allex, had been killed by his captors, the Islamist Shebab group.

The Shebab has denied that Allex is dead and also say they are holding a wounded member of the French assault team.