THE HAGUE, (Reuters) - Syria's foreign minister vowed on Wednesday to swiftly rid the country of chemical weapons remaining after the downfall of the Bashar al-Assad's government, and appealed to the international community for help.

Asaad Hassan al-Shibani spoke during closed-door meetings at the Organisation for the Prohibition of Chemical Weapons (OPCW) in The Hague, where he became the first Syrian foreign minister to address the disarmament agency. 

Following a sarin gas attack that killed hundreds of people in 2013, Assad-led Syria joined the agency under a U.S.-Russian deal and 1,300 metric tons of chemical weapons and precursors were destroyed.

But three inquiries - by a joint U.N.-OPCW mechanism, the OPCW's Investigation and Identification team, and a U.N. war crimes probe - concluded that Syrian government forces under Assad used the nerve agent sarin and chlorine barrel bombs in attacks during the civil war that killed or injured thousands.

As part of membership, Damascus was supposed to undergo inspections but for more than a decade the OPCW was prevented from uncovering the true scale of the chemical weapons programme.

"Syria is ready ... to solve this decades-old problem imposed on us by a previous regime," Shibani told delegates.

"The legal obligations resulting from breaches areones we inherited, not created. Nevertheless, our commitment is to dismantle whatever may be left from it, to put an end to this painful legacy and ensure Syria becomes a nation aligned with international norms."

Earlier on Wednesday, OPCW chief Fernando Arias called Syria's political shift "a new and historic opportunity to obtain clarifications on the full extent and scope of the Syrian chemical weapons programme".

Shibani said planning had begun, but that the help of the international community would be critical. Syria would require technical assistance, logistical assistance, capacity building, resources and expertise on the ground, he said.

"Although the Assad regime stalled for many years, we understand the need to act quickly, but we also understand that this needs to be done thoroughly. For that, we cannot succeed alone," he said.

Syria's declared stockpile has never accurately reflected the situation on the ground, OPCW inspectors have concluded. They now want to visit roughly 100 sites that may have been tied to Assad's decades-old chemical weapons programme.

(Reporting by Anthony Deutsch; Editing by Alex Richardson)