Britain's defense secretary said Friday that NATO had no "divine right to exist" and must reform to stay relevant and survive.

In an interview with the Associated Press before a security conference in Germany, John Reid said NATO "has to constantly ensure it is relevant for today's world and today's tasks ... and therefore I will be encouraging my colleagues in Munich to realize it is necessary we move to transform ourselves precisely in order to be effective and relevant."

"NATO has been probably the most effective defense organization in world history, but no institution has the divine right to exist," Reid added, calling for more flexibility and better coordination with the European Union.

U.S. Defense Secretary Donald Rumsfeld and German Chancellor Angela Merkel are among those attending this weekend's annual international security conference in Munich.

Launched in the 1960s, the Munich conference is favored by top policy makers and experts as a chance to exchange ideas in a more relaxed setting than formal international meetings. The main theme this year is "the renewal of trans-Atlantic relations." Other topics will include the West's relations with Russia, reform of NATO and Asian security concerns.