The US-Russian deal brokered Saturday to eliminate Syria's chemical weapons will be difficult if not impossible to implement, experts said, not least because of the quandary of their destruction.

The landmark deal thrashed out in Geneva gives Syria a week to hand over details of the regime's stockpile, which it aims to destroy by mid-2014 in order to avert US-led military strikes.

But chemical weapons expert Jean Pascal Zanders said that timetable is irrelevant because decision-making now passes to the Executive Council of the Organisation for the Prohibition of Chemical Weapons (OPCW).

Based in The Hague, the OPCW is charged with implementing the Chemical Weapons Convention, which Syria asked to join amid growing calls for military action against Damascus.

"The Executive Council has sovereign decision-making, and the US and Russia just have one vote each among the 41 members, so I wouldn't be surprised if we don't have consensus decision-making," Zanders told AFP.

"All deadlines proposed in the bilateral document (in Geneva) will only start running once the (Executive Council) decision has been taken," said Zanders, who runs a consultancy and blog dedicated to disarmament.

The OPCW's Executive Council is currently set to meet on Wednesday, but a source close to the matter said that date might be pushed back to Thursday or Friday.

Even once inspectors are deployed and stockpiles are found, they face the practical problem of destruction, said Olivier Lepick of the Foundation for Strategic Research in Paris.

"You have to build a factory that costs several hundreds of millions of dollars to then be able to destroy the chemical weapons," Lepick told AFP.

In Iraq, weapons inspectors used innovative but problematic methods to destroy Saddam Hussein's weapons of mass destruction, Zanders said.

"Sometimes holes were dug in the desert, fuel was put in it and a certain type of detonation was created that equals the effect of a fuel air bomb as a result of which you had high temperature incineration, which was not necessarily contained or controlled."

Taking the weapons out of Syria would also be a problem.

"The CWC (Chemical Weapons Convention) says chemical weapons and their ingredients cannot be transferred and no state party can under whatever circumstances acquire them in any way," Zanders said.

Syrian foe Israel is one of a handful of countries not to have ratified the CWC, and as it is the only one with a border with Syria, sending them there would "be the only option that's not prohibited by the CWC," he said.

"But I don't know what Bibi's (Israeli Prime Minister Benjamin Netanyahu) reaction would be to get them on Israeli territory."

For the same reason, taking the weapons to either the United States or Russia would also not be possible.

"Even assuming the US or Russia would be willing to accept these weapons on their soil, they have national laws prohibiting the transport of these weapons between states," Zanders said.

But, he added: "I do believe that people can be creative with the law."

Lepick said he thought it would be impossible for Syrian stockpiles to be destroyed by mid-2014, noting that the United States and Russia have still not destroyed their chemical weapons despite spending billions of dollars trying to do so since 1993.

The mid-2014 deadline "seems to be a complete fantasy", Lepick told AFP.

"Given the civil war, I don't think it can happen... In peacetime it would take years to dismantle Syria's chemical arsenal."

Former Iraq UN weapons inspector David Kay told CNN on Saturday that "doing this in the context of a civil war with a considerable amount of force used on both sides makes it very difficult."

It will also be difficult to find the right people for the job of inspection.

"It will take time to assemble them. Quite frankly, with my experience in Iraq, some of the people will not want to go into a combat zone."