International inspectors have completed their inventory of Libya's chemical weapons stockpiles, reporting more than 20 tons of mustard gas and the materials to make thousands of tons of sarin nerve gas, the world's watchdog organization said Monday.

The inspectors confirmed the disabling of Libya's sole chemical weapons factory and have inventoried material at two storage facilities, said the Organization for the Prohibition of Chemical Weapons (search), as Tripoli moved to keep its pledge to eliminate its potential to build weapons of mass destruction.

The OPCW oversees compliance with the 1993 international treaty banning chemical weapons, which Libya joined last month.

Under a timetable outlined in the treaty, Libya must complete the destruction of all weapons and facilities by April 2007.

Col. Moammar Gadhafi's (search) regime also is working with inspectors from the International Atomic Energy Agency (search) to dismantle its nuclear weapons programs.

Libya has moved swiftly since announcing in December it was scrapping its nuclear and chemical weapons programs, hoping to end international sanctions and regain full relations with the United States and other countries. Washington has already lifted most sanctions.

The OPCW said the inspections were completed on Friday, two weeks after Libya handed over a declaration of its weapons program that filled 14 file cartons.

Among the potential weapons declared and verified were 50,700 pounds of mustard gas and 2.9 million pounds of precursor chemicals for the production of nerve gas, the OPCW said in a statement.

Inspectors have also witnessed the destruction of more than 3,500 aerial bombs designed for chemical payloads. None was filled with chemicals, however.

OPCW Director-General Rogelio Pfirter said Libya's actions so far were "heartening," and that he expected Libya to continue cooperating.

More than 160 countries are members of the treaty, including the world's largest possessors of chemical weapons, the United States and Russia. Only a handful of large countries — including Angola, North Korea, Egypt, Iraq, Lebanon, Somalia and Syria — have yet to join.