"Following a process of consultations, Allies approved today Secretary General Anders Fogh Rasmussen's fifth year in office, thus extending his mandate until July 31st 2014," it said in a statement.

Rasmussen, 59, served as premier of Denmark from 2001 to 2009 and is NATO's 12th secretary-general.

The statement announcing the extension of his four-year mandate said the allies would support Rasmussen "in his dedicated work to carry forward NATO's tasks, missions and objectives, based on consensual allied decisions".

Under the terms of the alliance, which is headquartered in Brussels, its 28 member states are committed to mutually defend each other in case of external attack.