International inspectors were on Friday gearing up to disable the chemical weapons programme in war-hit Syria after reporting "encouraging" progress in a day of meetings with regime officials.
The Syrian regime and its armed opponents have both been accused of carrying out numerous atrocities in the 30-month conflict, which began as a popular uprising and has since snowballed into a full-blown war that has killed 115,000.
In a television interview, President Bashar al-Assad again denied having perpetrated August 21 chemical attacks on the outskirts of Damascus that killed hundreds and prompted Washington to threaten military action.
Syria's chemical arsenal -- to be destroyed under a UN resolution -- were in the hands of "special forces" who were the only ones capable of using them, Assad said.
"Preparing these weapons is a complex technical operation... and a special procedure is necessary to use them which requires a central order from the army chief of staff. As a result it is impossible that they were used," he said.
A team of inspectors from the Organisation for the Prohibition of Chemical Weapons and the United Nations has been tasked with implementing the resolution to destroy the banned arsenal by mid-2014.
They arrived in Syria on Tuesday, and reported "encouraging initial progress" after a day of meetings with the authorities on Thursday.
"Documents handed over yesterday by the Syrian government look promising, according to team members, but further analysis, particularly of technical diagrams, will be necessary and some more questions remain to be answered," it said.
The team said it hopes to begin on-site inspections and the initial disabling of equipment "within the next week".
The 19-member OPCW team faces a daunting task, as Syria is understood to have more than 1,000 tonnes of the nerve agent sarin, mustard gas and other banned arms at dozens of sites.
Their immediate aim is to disable production sites by late October or early November using "expedient methods" including explosives, sledgehammers and pouring concrete, an OPCW official said.
It is The Hague-based organisation's first mission in a country embroiled in a civil war.
The conflict has forced 2.1 million Syrians to flee their homeland, and nearly another six million people are displaced inside the country, hundreds of thousands trapped in besieged towns and neighbourhoods.
On Wednesday, the Security Council demanded "unhindered humanitarian access" across the conflict lines "and, where appropriate, across borders from neighbouring countries".
Syria has blocked aid missions from those nations, saying supplies will go to rebels.
Since the beginning of the uprising, the Council had been deadlocked over Syria, as Russia defended Assad, and last week's arms resolution and Wednesday statement are a breakthrough that helped avert potential US and French military action against the regime.
In the interview with opposition Turkish channel Halk TV, Assad said Syria's neighbour would pay for supporting the rebellion.
Turkey's parliament on Thursday extended for one year a mandate that would allow the country to send troops to Syria if necessary.
"In the near future these terrorists will have an impact on Turkey. And Turkey will pay very dearly for its contribution," Assad said.
Reacting to his remarks, anti-Assad protesters took to the streets in flashpoints across the country, under the slogan "Thank you, Turkey".
Meanwhile, the violence raged on.
Fierce battles gripped Barzeh in northern Damascus, as troops pressed a campaign aimed at crushing rebel enclaves around the capital, said the Syrian Observatory for Human Rights.
In Hasakeh in the north, there was fighting between the jihadist Islamic State of Iraq and the Levant and Kurdish forces, leaving an unknown number of dead on both sides, said the Observatory.
Doctors Without Borders (MSF) said, meanwhile, that tens of thousands of refugees fleeing Syria into Iraq in recent weeks have made an arduous journey by foot through the desert.
"Most of the refugees arrive at the border on foot after a long journey through a desert valley in intense heat. Many have left everything behind: family members, homes, and belongings," it said.
The statement was issued after some 60,000 Syrians fled to Iraq since August 15.