The United States will destroy the most dangerous of Syria's chemical weapon stockpile on a ship at sea, the world's chemical watchdog said on Saturday.
"The neutralisation operations will be conducted on a US vessel at sea using hydrolysis," the Organisation for the Prohibition of Chemical Weapons said in a statement.
"Currently a suitable naval vessel is undergoing modifications to support the operations and to accommodate verification activities by the OPCW," The Hague-based watchdog added.
The ship operation will destroy what is known as "priority chemical weapons", the most dangerous of Syria's total arsenal and ones that have to be out of the country by December 31 under an international deal agreed to avert military strikes on Damascus.
OPCW spokesman Michael Luhan on Saturday declined to name the vessel to be used.
OPCW member states have been thrashing out the details of how to destroy Damascus's arsenal ahead of the watchdog's annual meeting set to start on Monday.
A final plan for the destruction of Syria's chemical weapons — on land or at sea — is due to be approved by December 17.
The OPCW earlier this month adopted a final roadmap for ridding Syria of its arsenal of more than 1,000 tonnes of dangerous chemicals by mid-2014.
According to this roadmap, the "priority" weapons have to be removed from Syria by December 31 and destroyed by April 2014 and the rest by mid-2014.
The OPCW said on Saturday that 35 commercial companies have expressed an interest in destroying the lower priority, less dangerous weapons.
The watchdog's director-general Ahmet Uzumcu said the various companies will now undergo evaluation before a suitable candidate is found.
"The companies bidding for participation in the disposal process will be required to comply with all applicable international and national regulations pertaining to safety and the environment," Uzumcu added.
Chemical weapons experts in the past have expressed concern over the incineration of chemical weapons at sea due to the risk of toxins that may land up in the water.
Despite international consensus on destroying the chemicals outside war-wracked Syria, no country had volunteered to have them destroyed on its soil.
Syria is cooperating with the disarmament and has already said it had 1,290 tonnes of chemical weapons and precursors, or ingredients, as well as over 1,000 unfilled chemical munitions, such as shells, rockets or mortars.
A team of UN-OPCW inspectors has been on the ground since October checking Syria's weapons and facilities.
The destruction of declared chemical weapons production facilities was completed last month and all chemicals and precursors placed under seal, the OPCW said last month ahead of a November 1 deadline backed by a UN Security Council resolution.
Some chemical weapons are destroyed through a process known as hydrolysis, in which agents, like detergents, are used to neutralise chemicals such as mustard gas and sulphur, resulting in liquid waste known as effluent.
Nerve gases such as sarin are often better destroyed through incineration.
The OPCW has before requested that 798 tonnes of chemicals needed to be disposed of, as well as 7.7 million litres of effluent.