From Russia to the United States, Iraq and Libya, inspectors from the Hague-based Organization for the Prohibition of Chemical Weapons (OPCW) have been slowly but surely destroying the world's most dangerous chemical stockpiles.

Syria last month signed up to the Chemical Weapons Convention (CWC), which the OPCW enforces, agreeing to hand over its chemical weapons for destruction under a Russia-US plan aimed at averting military strike on the country in the wake of an alleged devastating chemical attack on a Damascus suburb.

Previously one of only five countries not to have signed the global treaty, Syria accepted the Russian proposal last month and has so far won rare praise for its cooperation with OPCW's inspectors, who are already hard at work.

Ahead of the surprise announcement, the organization said it preferred to focus on the task in Syria rather than any jubilation.

"We don't want to give any impression that we're focused on anything else than other than this mission," OPCW spokesman Michael Luhan said.

The organization is expected to hold a press conference later on Friday.

The organization began work in 1997 and has overseen the destruction of some 57,000 metric tons of chemical weapons, mostly US and Russian arsenals.

"It's the slow steady laying down of bricks over the weeks, months and years, people sitting in control rooms watching this stuff going into the chutes," Luhan said.

"It's our persistence, without any fanfare... it's the slow grinding work that we hope over time will be more appreciated."

The OPCW's work was the "subject of years and years of patient diplomacy in which we've demonstrated that we do diplomacy very, very well. We've kept everybody aboard, we keep adding states parties, we're approaching universality."

But Luhan said he did not want the awarding of the Nobel Peace Prize to overshadow its dangerous mission in Syria.

"We don't want to be seen as a one-note song," he said.

Chemical weapons were first used in combat in World War I, and again in 1988 Iraqi-imposed war on Iran by the Saddam regime, with Chemical Weapons Convention finally drawn up in 1993 in Paris.

The CWC entered into force on April 29, 1997, and the OPCW began its work on the edge of a quiet upmarket leafy suburb in The Hague shortly afterwards.

BA/BA