Washington: The US military jets destroyed two surface-to-air missiles sites belonging to the Muammar Gaddafi regime as a part of North Atlantic Treaty Organization (NATO) mission in Libya.

After April 1, when NATO took the lead of multilateral operations in Libya, US military aircraft have flown more than 800 sorties in support of Operation Unified Protector.

More than 150 of those sorties have been “suppression of enemy air defense” missions, eight of which included ordnance drops, Pentagon officials said.

The tempo of NATO operations in Libya remains high, alliance spokesman Oana Lungescu told reporters from NATO headquarters in Belgium.

“We are keeping up the pressure on the Gaddafi regime forces to stop their brutal onslaught against civilians. It's a challenging task, but we are making significant progress in weakening Gaddafi's ability to use his military machine against his own people,” she said.

In a statement NATO said its air forces continue to degrade the Gaddafi regime’s ability to harm civilians.

“This campaign has been successful. We are seeing the results in reduced activity in regime held areas. But Gaddafi forces continue to cause harm to civilians in the Misuratah and other areas,” said Lieutenant-General Charles Bouchard, Commander of Operation Unified Protector.

“In the next few days, we will maintain the pressure on regime front-line troops to show NATO is resolute in its determination to protect civilians. We will continue to strike at regime forces as long as they continue to attack their own people,” he added.