NATO Secretary General Anders Fogh Rasmussen said on Monday that military action alone won't solve the crisis in Libya.

"I have taken note of an African Union ceasefire proposal ... I want to be clear: there can be no solely military solution to the crisis in Libya." he told a press conference.

South African President Jacob Zuma said on Sunday after his talks with Gaddafi in Tripoli that the Libyan leader had accepted the "roadmap" presented by the AU to end conflicts and open political dialogues with rebels.

The NATO chief stressed "any ceasefire must be credible and verifiable," saying Libyan leader Muammar Gaddafi announced ceasefire in past but failed to keep his promises.

However, he said it was too early to talk about how to establish a kind of mechanism to monitor the ceasefire.

The military alliance has stepped up its attacks against Libyan government forces since Saturday, mainly near Misrata and Ajdabyia, where pro-Gaddafi forces are fighting fiercely with rebel fighters.

"Since Saturday morning, NATO aircraft have flown almost 300 sorties. We have destroyed 49 tanks, 9 armored personnel carriers, 3 anti-aircraft guns and 4 large ammunition bunkers," Rasmussen said, adding "our operational tempo will be determined by this clear goal to protect civilians against any attack.

He said that NATO had not considered "more robust measures" in Libya, denying suggestions by some Western countries, including arming rebel fighters or sending ground forces.

"We have no consideration as to taking more robust measures. We are focused on the implementing the United Nations Security Council's resolution fully. At this stage, we don't see any needs for strengthened measures," the NATO chief said.

Foreign ministers from 28 NATO countries, along with its partners, are scheduled to meet in Berlin on Thursday and Friday to discuss the Libyan crisis.