TRIPOLI, Libya – NATO Secretary-General Anders Fogh Rasmussen landed in Libya Monday to declare an official end to the seven-month aerial bombing campaign that helped depose longtime ruler Moammar Gadhafi.

“We had been mandated by the United Nations Security Council to protect civilians and that, basically, has been a great success,” he told CNN during the flight from Brussels, Belgium. “We have prevented a massacre. We have saved countless lives. We have fully implemented the United Nations mandate. That was our mission and we have done what we promised to do.” NATO’s move comes after the United Nations Security Council last week rescinded its March mandate for military intervention to protect civilians targeted during anti-regime protests.

Susan Rice, the U.S. ambassador to the United Nations, said NATO’s mission puts Libya on a path to freedom.

But she tempered her remarks with a word of caution.

“We’re very concerned that, as we move forward, that the authorities make maximum effort to swiftly form an inclusive government that incorporates all aspects of Libyan society, and in which the rights of all Libyan people are fully and thoroughly respected, regardless of their gender, their religion, their region of origin,” Rice said after the Security Council vote last Thursday.

“But for the United States, and, I think, for the United Nations Security Council, this closes what I think history will judge to be a proud chapter in the Security Council’s history.”

Momentum to end the campaign began building after Gadhafi was killed following his capture near his hometown of Sirte on Oct. 20.

Many British military personnel who had been stationed at an Italian airfield for the campaign already are returning home.

Meanwhile, Gadhafi’s relatives said they plan to file a war crimes complaint.

“All of the events that have taken place since February 2011 and the murder of Gadhafi, all of this means we are totally in our right to call upon the International Criminal Court,” Marcel Ceccaldi, a lawyer representing the family, said last week.

Questions have been raised about how Gadhafi was killed.

Amateur videos showed him alive when captured by the opposition. He died from a shot in the head, officials said, but the circumstances surrounding the shot remain unclear.

NATO’s Libya campaign began in March, after the Security Council adopted Resolution 1973, which imposed a no-fly zone in the country’s airspace and authorized member states to take measures to protect civilians.