NATO has decided to move warships to the central Mediterranean to enhance monitoring the situation in Libya, the alliance's chief said on Thursday.

"We have decided to increase the presence of NATO maritime assets in the central Mediterranean ... These ships will improve NATO's situational awareness, which is vital in the current circumstances, and they will contribute to our surveillance and monitoring capability, including with regard to the arms embargo established by the UN Security Council," Anders Fogh Rasmussen said at a press conference following a meeting of NATO defense ministers.

Rasmussen said that the ministers had designated NATO military authorities to develop "detailed planning" concerning humanitarian aid and enforcing arms embargo.

However, the ministers failed to reach an agreement on the imposition of a no-fly zone over Libya amid divisions between allies.

The NATO chief said that NATO must have a "demonstrable need" for action, a "clear legal basis" and "firm regional support" to launch operation to tackle the Libya crisis.