UNITED NATIONS — Iraq has given the United Nations its ratification of the treaty banning chemical weapons, a move welcomed by the U.N. chief as a demonstration of the country's commitment to disarmament and nonproliferation.

Iraq will be bound by the treaty in 30 days, becoming the 186th nation to be a party to the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction.

After the first Gulf War in 1991, U.N. weapons inspectors spent years uncovering and destroying Iraq's extensive chemical weapons program including nearly 40,000 filled and empty chemical munitions, 690 tons of chemical weapons agents, more than 3,000 tons of precursor chemicals to make weapons, and hundreds of pieces of equipment to produce them.

In the 3½ months before the 2003 Iraq war, when U.N. inspectors were allowed back into Iraq after a nearly four-year ban, they found no evidence that Saddam Hussein had maintained chemical weapons stockpiles or had resumed production.

Iraq's U.N. Ambassador Hamid al-Bayati, who handed over the ratification document signed by the Iraqi Presidential Council, said it reflected the government's willingness to cooperate with the international community in the field of disarmament and its determination to participate in maintaining international peace and security.

Under a June 2007 Security Council resolution that disbanded the U.N. weapons inspection operation for Iraq, the Iraqi government was required to become a party to the chemical weapons convention.

U.N. Secretary-General Ban Ki-moon congratulated Iraq and urged holdout nations to sign on as soon as possible to give the chemical weapons convention universality, U.N. spokeswoman Michele Montas said.

Angola, Egypt, North Korea, Somalia and Syria have not signed the 1997 treaty. The Bahamas, Dominican Republic, Israel and Myanmar have signed the convention but not ratified it.

Six countries have acknowledged having weapons capabilities and pledged to dismantle them.