NATO's decision-making body granted approval Wednesday for the military alliance to continue its mission over Libya for another 90 days.
Libya's former leader, Moammar Gadhafi, has fallen from power but pockets of loyalist resistance remain.
NATO took over command of the mission in March, enforcing a U.N. resolution allowing the imposition of a no-fly zone and action to protect civilians. Some observers have said NATO's actions, which have included daily bombing runs over the North African country, were more robust than envisioned in the resolution and amounted to supporting the rebels in a civil war.
But NATO Secretary-General Anders Fogh Rasmussen defended the operation in a statement Wednesday.
"Together with our partners, NATO has been remarkably successful in fulfilling the mandate of the United Nations," he said. "But while threats to civilians persist, we will continue to protect them under the mandate confirmed unanimously in U.N. Security Council Resolution 2009, and at the request of the National Transition Council."
The council is forming Libya's new government.
The additional 90 days was approved Wednesday in Brussels by the North Atlantic Council, which is composed of representatives from NATO's 28 member countries.
NATO took command of the operation in March and extended it for another 90 days in June. Without the new extension, permission for the operation would have expired Sept. 27.
Fogh Rasmussen said the mission would be under constant review and could end at any time.
"This decision sends a clear message to the Libyan people: We will be there for as long as necessary, but not a day longer, while you take your future in your hands to ensure a safe transition to the new Libya," he said.