The 189 nations participating in the 2010 Review Conference on Nuclear Non-proliferation Treaty (NPT) approved on Friday a final document towards nuclear disarmament, including the establishment of a nuclear weapon-free zone in the Middle East.

"The NPT must be at the center of our global efforts to stop the spread of nuclear weapons around the world, while pursuing the ultimate goal of a world without them," Obama said in a statement.

The agreement, he said, includes "balanced and practical steps that will advance non-proliferation, nuclear disarmament, and peaceful uses of nuclear energy, which are critical pillars of the global non-proliferation regime."

The declaration states that a conference "on the establishment of a Middle East zone free of nuclear weapons and all other weapons of mass destruction" should be conveyed in 2012.

The United States has long supported such a zone, Obama said. However, "comprehensive and durable peace in the region and full compliance by all regional states with their arms control and nonproliferation obligations are essential precursors for its establishment," he said.

The document urges Israel, which has not signed the NPT and is believed to possess nuclear weapons, to sign the treaty and place "all its nuclear facilities under comprehensive safeguards of the International Atomic Energy Agency (IAEA)."

Obama said the U.S. authorities "strongly oppose efforts to single out Israel and will oppose actions that jeopardize Israel's national security." Israel is U.S.'s major strategic ally in the Middle East.

The U.S. President said Iran, which is accused by Western powers of attempting to build nuclear weapons under the guise of peaceful energy generation, was the "greatest threat" to nuclear non-proliferation in the region.

Those nations that fail to meet their non-proliferation obligations must "face consequences," Obama said.

The Iran Six, which comprises Britain, China, France, Germany, Russia, and the U.S., have been in talks on new sanctions to be imposed on Iran over its controversial nuclear activities.

"Together, we must work for a world where nation's benefit from the peaceful power of nuclear energy, while also being secure from the threat posed by nuclear proliferation," the U.S. president said.