NATO defense ministers on Thursday approved a "Ministerial Guidance" for modern operations to cope with the changing security situation, said NATO spokesman James Appathurai.
The document represents a "new level of ambition for the alliance's force structure," he told reporters after a meeting of the Defense Planning Committee.
"It is a substantial realignment of the way in which NATO will plan and structure its forces."
NATO's tasks have undergone fundamental changes since the end of the Cold War in the early 1990s and again after the 9/11 terrorist attacks in 2001.
"We no longer need to prepare for one big war. We have to prepare for and indeed carry out a multitude of military operations," said Appathurai.
This ministerial guidance recognizes that NATO may have to conduct two major joint operations and six smaller ones at the same time, said the spokesman.
Major operations are full-sized ones that may involve up to 60,000 troops while small operations are division-sized with 20,000 to 30,000 soldiers, he said.
Asked whether NATO is capable of carrying out these operations which altogether may need up to 300,000 troops, Appathurai said these targets are "ambitious, but can be met."
NATO Assistant Secretary General John Colston said Tuesday that the 26-member alliance has a troops pool of 1.4 million.
The ministerial guidance also sets out guidance to ensure NATO has effective arrangements to work with other players, such as the United Nations, the European Union, the Group of Eight most industrialized nations and non-governmental organizations, said the spokesman.
The ministerial guidance provides details for the Comprehensive Political Guidance, a document which has already been endorsed by NATO member states.
Through the Comprehensive Political Guidance, the ministers on Thursday committed to endeavoring to meet the target of 2 percent of GDP devoted to defense spending. Only seven member states are meeting this target, said Appathurai.
Prior to the Defense Planning Committee meeting, the ministers convened for a Nuclear Planning Group meeting, at which the nuclear status of NATO nuclear forces was discussed.