Syrian troops wrested control of a key road linking the government-held heartland with the embattled northern city of Aleppo, reopening the crucial supply route after heavy fighting with rebels, state media and activists said Monday.

Government forces and opposition fighters have been locked in a bloody, block-by-block fight for Aleppo since rebels launched an assault on the city 15 months ago. The battle has been locked in a stalemate, with neither side willing to relent with control of Syria's largest city at stake.

With much of the northern countryside now in opposition hands, a cat-and-mouse game has emerged over the past year as the rebels try to cut the government supply lines to the regime's remaining troops in the north, particularly in Aleppo.

After the rebels cut the main north-south highway late last year, President Bashar Assad's regime built a desert road to bypass contested areas. Opposition fighters responded by severing the alternate route — a winding road that runs northeast from the city of Hama — in August.

It was that desert road that regime troops reopened late Sunday, according to Syria's state news agency and the Britain-based Syrian Observatory for Human Rights activist group.

"Control of that road was life or death for the future of the regime in Aleppo and for the citizens under the control of the regime," Observatory director Rami Abdul-Rahman said. "It's important, because now they (the government) can extend supplies to Aleppo."

Still, he said, the road remains "very dangerous" and susceptible to ambushes.

The state news agency said the military "broke the siege of armed terrorist groups that were preventing food supplies from reaching residents of Aleppo." The government refers to rebels as terrorists.

Meanwhile, several members of an advance team of experts from the Organization for the Prohibition of Chemical Weapons returned to their headquarters in The Hague, Netherlands, after holding what they called "constructive" talks with the Syrian government about its initial disclosures on its chemical program.

The OPCW said in a statement that Syrian authorities have been "cooperative," and that the experts will continue to evaluate the information handed over by the government.

The disarmament experts have been sent to Syria as part of a deal unanimously endorsed by the U.N. Security Council last month to rid the country of its chemical weapons by mid-2014.

For the first time since the mission began last week, Syrian personnel working under the supervision of the OPCW experts on Sunday began destroying the country's chemical arsenal and equipment used to produce it.

In Indonesia, U.S. Secretary of State John Kerry said the United States and Russia are "very pleased" with the mission's progress so far, and called the steps taken Sunday "a good beginning."

The joint OPCW-U.N. mission to scrap Syria's chemical program stems from a deadly Aug. 21 attack on opposition-held suburbs of Damascus in which the U.N. has determined the nerve agent sarin was used. Hundreds of people were killed, including many children. The U.S. and Western allies accuse the Syrian government of being responsible, while Damascus blames the rebels.

The Obama administration threatened to launch punitive missile strikes against Syria, prompting frantic diplomatic efforts to forestall an attack. Those efforts concluded with September's unanimous U.N. Security Council resolution endorsing the elimination of Syria's chemical weapons.

The resolution also endorsed a roadmap for a political transition in Syria adopted by key nations last year, and called for an international peace conference to be held in Geneva. U.N. chief Ban Ki-moon suggested November for the peace talks, although questions have been raised whether the government or the opposition could be coaxed to the table.

U.N. spokesman Martin Nesirky said Monday that Ban "continues to believe that this can take place in mid-November, and it's his firm determination to seek to make that happen."

"Everyone knows that it is not easy, that it is going to be difficult to bring the sides to the table," Nesirky said.

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Associated Press writers Ryan Lucas and Diaa Hadid in Beirut, and Edie Lederer at the United Nations contributed to this report.

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Follow Bassem Mroue on twitter.com/bmroue