The US military has carried out air strikes against ISIS-controlled Libya, marking the first such offensive operation.

Pentagon Press Secretary Peter Cook said that the precision air strikes were conducted on Monday following a request from the Libyan Government of National Accord (GNA).

These strikes, targeting ISIS tank and vehicles, support GNA-affiliated forces in their fight to recapture Sirte, where ISIS has a stronghold.

"The first strikes started today in positions in Sirte, causing major casualties."

The Guardian reported that the air strikes were carried out by drones and warplanes.

GNA Prime Minister Fayez Serraj was quoted by The Associated Press as saying: "The presidency council, as the general army commander, has made a request for direct US support to carry out specific airstrikes.

"The first strikes started today in positions in Sirte, causing major casualties."

Serraj further said that US ground troops will not be deployed to support the mission in northern Libya.

The strikes were authorised by President Barack Obama following a recommendation from US Defense Secretary Ash Carter and Joint Chiefs of Staff chairman Joe Dunford.

Cook said that GNA-aligned forces have had success in recapturing territory from ISIS thus far around Sirte, and additional US strikes will continue to target ISIS in Sirte.

The actions taken by the US will help deny ISIS a safe haven in Libya from which it could attack the US and allies, Cook further added.