The members, meeting at the UN in New York, called for a conference in 2012 to be attended by Middle Eastern states - including Iran - to establish the zone.

The document also said Israel should sign the NPT.

But the US said the reference to Israel could jeopardise efforts to persuade the Israelis to attend the 2012 talks.

The NPT has suffered from deep divisions between states who have nuclear weapons and those who do not, says the BBC's United Nations correspondent Barbara Plett in New York.

It is seen as the cornerstone of global disarmament efforts, she adds.

The 28-page final declaration was agreed following intense talks on the last day of a month-long conference.

The document calls for the United Nations secretary general to organise a meeting of Middle East states in 2012 to agree to the creation of a "zone free of nuclear weapons and all other weapons of mass destruction".

"All eyes the world over are watching us," said conference president Libran Cabactulan, of the Philippines, as the final text was approved.

Egypt's Maged Abedelaziz, speaking for the Non-Aligned Movement of 118 developing nations, welcomed the decision, saying it was "an important step forward towards the realisation of the goals and objectives of the treaty".