NATO Secretary-general Anders Fogh Rasmussen said on Monday that the alliance had no intention to intervene in Libya's crisis, but would be ready for all eventualities.

"NATO has no intention to intervene in Libya. But as a defense alliance and a security organization, our job is to conduct prudent planning for any eventuality. We assume that an operational role would be in accordance with and pursuant to a UN Security Council mandate," Rasmussen told a press briefing in Brussels.

But if the humanitarian situation in Libya keeps worsening, "I can't imagine the international community and the United Nations standing idly by," Rasmussen warned.

He also noted that the imposition of a no-fly zone over Libya would be very complex and require a "wide range of military assets."

The unfolding situations in Libya and the region will be on top of the agenda as defense ministers for the 28 NATO countries convene on Thursday and Friday in Brussels, he said.