Pentagon officials said on Monday they believe they hit Mokhtar Belmokhtar in an airstrike on Sunday in eastern Libya.
But uncertainty still surrounds the US airstrike in eastern Libya, and whether Belmokhtar, the one-eyed, al-Qaida-linked commander who led a deadly attack on an Algerian gas facility in 2013, was actually among the militants said to have been killed in the bombing.
Libyan officials said the strike hit a gathering of militants on a farm outside Ajdabiya - a coastal city about 850 kilometres (530 miles) east of the capital, Tripoli - but there were conflicting reports on how many people died.
A Pentagon spokesman said an initial assessment showed the bombing that targeted Belmokhtar was successful, but also said that "post-strike assessments" were still underway to determine whether the Algerian militant had definitely been killed.