The U.N. Security Council in March sanctioned military action in Libya to protect civilians from attacks by forces loyal to Moammar Gadhafi. NATO has operated under that capacity during Operation Unified Protector.
Libyan rebels took control over Tripoli in August and much of the international community has recognized the National Transitional Council as the sole governmental authority in Libya.
Forces loyal the NTC are fighting pro-Gadhafi fighters in parts of the country and the former leader remains on the run.
Carmen Romero, a spokeswoman for NATO, told reporters that it was "premature" to set a timetable for when the mission would end.
"We are very close to the end but there are still threats to the population," she said. "And as long as these threats persist, we will continue with our operation."
Any decision to end Operation Unified Protector must come from NATO after it reviews the situation in Libya. The alliance, she added, would coordinate with the NTC and the United Nations in assessing the threat to the civilian population in Libya.
Canadian army Col. Roland Lavoie, the operation's military spokesman, said NATO forces were committed to the U.N. mandate to intervene.
"There should be no doubt that NATO remains ready to engage, using all necessary force against military assets that may represent a significant threat against civilians in Libya," he said.