US Special Operations 'providing ground support' to Libyan forces

The small elite of US personnel operate alongside British troops and help to coordinate American airstrikes and providing intelligence to partner forces.

Their role remains limited to providing direct support to Libyan forces loyal to the internationally-recognised unity government, the official added.

However, the head of Libya's Government of National Accord [GNA] said on Wednesday his country did not need foreign troops on the ground in the fight against IS.

"We do not need foreign troops on Libyan soil," Fayez al-Sarraj said in an interview with Italy's Corriere della Sera daily.

"Our men can manage alone once they have cover from the air. I only asked for US airstrikes which must be very precise and limited in time and geographical scope, always carried out in coordination with us," Sarraj said.

Pro-GNA forces have been engaged in a military operations since 12 May to retake the coastal city located 450 kilometres [280 miles] east of Tripoli.

Sirte has been a stronghold of the militant group since June last year.

The US has been carrying out airstrikes on IS positions in the city at GNA's request since last Monday.

Sarraj warned IS "will use any means possible to send its militants to Italy and Europe" and said he "would not be at all surprised to discover that its men hide out on boats" of migrants headed for the Italian coast.

Rome has authorised the US to use its bases and air space for strikes in Libya against IS.

Agencies contributed to this report