AMSTERDAM (Reuters) - The head of the mission overseeing the destruction of Syria's chemical arms said on Monday she had been unable to use a road along which toxic munitions must be hauled to a Syrian port for shipping abroad by December 31.
Fighting in Syria poses a major hurdle to implementing an agreement between Damascus and the Organisation for the Prohibition of Chemical Weapons (OPCW) to remove the deadliest chemicals by the end of the year to be destroyed on a U.S. ship, said Sigrid Kaag, who heads a U.N. mission with the OPCW.
"Security remains a key challenge for all. The destruction of a chemical weapons program has never taken place under such challenging and dangerous conditions," Kaag told delegates of the OPCW in The Hague.
She said the road between the capital Damascus and the city of Homs had been closed during a trip to the region last weekend, and she had instead travelled by helicopter to Latakia, the northern port from which Syria will export hundreds of tons of toxic chemicals to a floating destruction facility.
"The situation remains complex and the security situation volatile ... but we intend to forge ahead," Kaag said.
Fighting for control of the highway north of Damascus intensified two weeks ago when Syrian President Bashar al-Assad's forces took the town of Qara, about 80 km (50 miles) north of the capital, right next to the road.
Rebels hit back, attacking the town of Deir Attiyah, which the army recaptured on Thursday before turning its guns on Nabak, another town on the road, a few kilometers to the south.
Thousands of people have fled the fighting. Rebels say Assad's forces, backed by air power by day, have the advantage in daylight hours. But rebels say they are able to regroup in nearby hillsides and prevent the army from controlling the road.
The Hague-based OPCW, which won the Nobel Peace prize in October, has been charged with supervising the destruction of Syria's chemical arsenal under an agreement that averted U.S. missile strikes.
Under a deal worked out between the United States and Russia, Syria will relinquish control of its chemical weapons and destroy its entire stockpile of 1,300 tons of sarin, mustard gas and other lethal agents.
The size of the stockpile, including 800 tons of industrial chemicals destined for incineration at commercial toxic waste plants, means it can only be transported by land and sea. Syrian forces will have to transport the chemicals through contested territory to Latakia.
"For the program implementation and the removal out of country it is necessary the roads are open and safe to be used," Kaag said.
The United States is donating a ship and destruction equipment, but it has not yet reached agreement about where the naval vessel will anchor while it processes the toxic chemicals.
(Additional reporting by Dominic Evans in Beirut; Editing by Alistair Lyon)