THE HAGUE — All the elements for ridding Syria of its declared stockpile of toxic chemicals are in place but the unprecedented effort could be delayed, an official from the global chemical weapons watchdog said Tuesday after the group’s executive council reviewed the plan.
The Organization for the Prohibition of Chemical Weapons’ 41-nation council asked director-general Ahmet Uzumcu to report back Jan. 7 on progress in executing the Syrian plan, said the official, who spoke on condition of anonymity.
According to a detailed timetable agreed upon earlier, the most toxic chemicals in Syria’s weapons program — including precursors for sarin nerve gas — were to have been removed from the country by Dec. 31 and Syria’s entire chemical weapons program should be history by mid-2014.
But those ambitious deadlines have been cast into doubt by poor security in Syria, which is in the third year of a devastating civil war, and mundane logistical issues like getting trucks through customs and even through the severe winter weather that has buffeted the Middle East.
‘‘There is a possibility we may have to revisit the upcoming target date of Dec. 31,’’ the official said.
‘There is no excuse whatsoever for the treatment that he has suffered by the Syrian authorities.’
While the group did not release the plan, the official confirmed that most elements already were known, based on offers made publicly by several countries.
Syria will transport hundreds of tons of chemicals to its port of Latakia, where they will be put on board Danish and Norwegian ships and taken to an as yet unspecified port in Italy. There they will be transferred to a US government ship, the MV Cape Ray, which has machinery that will neutralize the chemicals by mixing them with other chemicals and heated water.
The Danish and Norwegian ships will return to Syria to pick up hundreds of tons of less-toxic chemicals that will be destroyed by private companies.
The group’s official, who was at the meeting, said the executive council ‘‘gave the director-general quite a clear go-ahead’’ to implement the plan.
The United States will use a mobile Field Deployable Hydrolysis System to process the most toxic chemicals, making them unusable as weapons.
The disarmament plan came into being after global outrage at a sarin attack on a Damascus suburb in August that killed hundreds of people, including many children. Washington and its allies blamed Syrian President Bashar Assad’s regime for the atrocity. Assad agreed to join the watchdog group and give up his chemical weapons program to ward off likely retaliatory US airstrikes.
Syria still denies responsibility for the Damascus attack.
In a separate development Tuesday, a minister in Britain’s Foreign Office accused the Syrian government of effectively murdering a UK doctor held in Syrian custody. Dr. Abbas Khan, a 32-year-old orthopedic surgeon from London, was seized by government troops in Aleppo, Syria, in November 2012 after he entered the country on a humanitarian mission.
Hugh Robertson, the head of the foreign office’s Mideast remit, lashed out at Syrian authorities, saying ‘‘the fact remains’’ that Khan went to Syrian to help the people there suffering amid a civil war.
‘‘There is no excuse whatsoever for the treatment that he has suffered by the Syrian authorities who have in effect murdered a British national who was in their country to help people,’’ Robertson said.
The Foreign Office had said earlier that it was ‘‘extremely concerned’’ by reports Khan had died in detention and that if true the responsibility for Khan’s death lies with Syrian authorities. There was no immediate response from the Syrian government.
Khan’s brother Afroze Khan, 34, said the Syrian security agency had promised that he would be freed this week, but when his mother went to visit him Monday, she was told that he had died.
A spokesman for George Galloway, a member of Parliament, said Syrian officials told him that prison guards who had taken breakfast to Abbas Khan on Monday had returned to check on him two hours later and found him hanging by his pajama bottoms from a hook in his cell.
Also Tuesday, an international aid group warned that hospitals in the northern Syrian city of Aleppo were overwhelmed with casualties, as government warplanes blasted opposition areas of the city as part of a withering three-day air assault that has killed more than 100 people.
The intensified air campaign suggests Assad’s government is trying to crush opposition in the contested city, Syria’s largest, ahead of an international peace conference scheduled for late January in Switzerland.