NATO's top official says ousted Libyan leader Muammar Gaddafi and his loyalists should stop trying to cling to power by force.

NATO Secretary-General Anders Fogh Rasmussen told reporters Thursday during a visit to Lisbon, Portugal that "Gaddafi and the remains of his regime must realise there's nothing to be gained by more fighting."

He says, "Libya is turning a new page."

He says the military alliance would not stand down while a threat to Libyan civilians remains.

He described NATO's operations in Libya as "a great success" and says the alliance has no confirmed information about possible civilian casualties.

Fogh Rasmussen says the United Nations will take the lead in helping Libya's peaceful transition to democracy.