"American jets conducted an operation which resulted in the deaths of Mokhtar Belmokhtar and a group of Libyans belonging to a terrorist organisation in eastern Libya," said a statement by the embattled Libyan government posted on Facebook.
The Pentagon confirmed that Belmokhtar had been the target of the strike by did not confirm that he had been killed.
The one-eyed jihadist leader's death has been reported several times before but he has apparently resurfaced and his group has remained active in north Africa and Mali, where France has been fighting Islamist insurgents.
The US has used drones to strike targets in north Africa in the past but the New York Times reports this was the first US air strike of any kind carried out in Libya since Moamer Kadhafi was toppled in 2011.
It hit a farm where Belmokhtar, who leads a group known as Al-Murabitoun and is a former leader of Al-Qaeda in the Islamic Maghreb, was meeting leaders of other armed groups, including Ansar al-Sharia, which is on the US's "terrorist" list.
The Libyan statement said the operation took place "after consultation with the Libyan transitional government", which is based in the east and fighting Islamist militias.
Prime Minister Abdullah al-Thani voiced his "support", saying the operation was "part of international aid that has long been sought in the fight against terrorism".
An Al-Murabitoun statement last month said it had pledged allegiance to the Islamic State armed group but Belmokhtar immediately vowed continued backing for Al-Qaeda in apparent evidence of a power struggle within the organisation.
Who is Mokhtar Belmokhtar?
- Born in 1972 in Algeria, Belmokhtar is one of the few jihadists in the Sahara region to have fought in Afghanistan. He took part in the war against the Soviet occupation in the 1980s and lost an eye in combat.
- In the 1990s he fought against the Algerian government as a member of the Armed Islamic Group (GIA), the military wing of the Islamic Salvation Front (Fis), which had been denied its election victory by military intervention.
- His special skills included kidnapping, the use of explosives and ambushes.
- He went on to become a joint founder of the Salafist Group for Preaching and Combat, which evolved into Aqim.
- In 2003 in Algeria he took part in the kidnapping of about 30 foreign tourists, some of whom were freed after a ransom was paid.
- He has at least three nicknames – “Khaled”, “Le Borgne” (One-eye), due to his disability, “the Uncatchable” because intelligence services couldn’t catch him and “Marlboro”, due to his business of smuggling of contraband cigarettes.
- An Algerian court sentenced him to death in 2008 for the murder of 13 customs officers.
- For nearly 10 years he was regarded as a key member of Aqim but reportedly fell out with Aqim chief Abou Zeid and formed the Khaled Abu al-Abbas Brigade, also known as Masked Brigade or the Signatories in Blood.
- In 2012 Signatories in Blood merged with the Mali-based Mujao to form Al-Maribatoun.
- Although some observers believed that he was devoting himself completely to smuggling and other criminal activity, he reappeared on the political front with the attack on the In Amenas gas plant in Algeria, in which 38 hostages and 28 jihadists died. He said that the assault was a reprisal for France’s military intervention in Mali and it became clear that he still had ties to Al-Qaida.
- Also in 2013 he personally supervised twin car bombings that killed at least 20 people in Niger.
- In 2013, a day after claiming that Abou Zeid was dead, the Chadian military claimed that it had killed Belmokhtar in an operation in the Ifogha mountains near the Algerian border in northern Chad.
- France, which was conducting the Mali campaign, did not confirm the report of his death and the US put a price of five million dollars on his head.
- Al-Maribatoun claimed responsibility for the March 2015 attack on a restaurant in Mali's capital, Bamako, in which a French national died.