Damascus - UN-Arab League envoy Lakhdar Brahimi, in Syria on Tuesday on the most sensitive leg of a regional push for peace talks, has warned of the 'Somalisation' of the war-ravaged country.
His grim warning came as fighting prevented chemical weapons inspectors from visiting two sites, although UN chief Ban Ki-moon said the mission to destroy Syria's arsenal by mid-2014 was still on track.
Brahimi has been seeking to build on the momentum of last month's US-Russian deal to eradicate Syria's chemical weapons in order to launch the so-called Geneva II peace talks proposed for next month.
But the talks have been cast into doubt by the increasingly divided opposition's refusal to attend unless President Bashar al-Assad agrees to step down, a demand rejected by Damascus.
In an interview with a French website published Monday, Brahimi said Assad could contribute to the transition to a "new" Syria but not as the country's leader.
"What history teaches us is that after a crisis like this there is no going back," the Algerian diplomat told the Jeune Afrique website ahead of his first visit to Syria since December, when he angered the regime by insisting that all powers be handed over to a transitional government.
The veteran troubleshooter admitted "the entire world will not be present" at the talks, but said the alternative to a political settlement could be a failed state in the heart of the Middle East.
"The real danger is a sort of 'Somalisation,' but even more deep and lasting than what we have seen in Somalia."
More than 115 000 people are estimated to have been killed in Syria's 31-month conflict, which erupted after the regime launched a brutal crackdown on peaceful pro-democracy protests.
In the latest blow to peace efforts, 19 Islamist rebel groups said Sunday that anyone who attends the Geneva talks would be committing "treason" and could face execution.
The warning added to doubts over whether any agreement reached by Syria's external opposition could be implemented on the ground.
In recent months rebel groups have clashed among themselves, and several prominent brigades have rejected the National Coalition - the main Western and Arab backed opposition group - which is to meet on 9 November to decide whether to take part in the Geneva talks.Sustained genuine commitment
The intensity of the fighting in Syria has meanwhile slowed the unprecedented international mission to dispose of a vast chemical arsenal in a country torn apart by civil war.
The Hague-based Organisation for the Prohibition of Chemical Weapons said on Monday its inspectors had been unable to reach the last two of 23 disclosed chemical weapons sites for "security reasons".
Inspectors were supposed to have visited all sites declared by Syria by Sunday as part of their mission to oversee the elimination of the country's chemical weapons by mid-2014.
UN chief Ban Ki-moon said the inspectors were still on track to destroy Syria's chemical weapons production equipment by 1 November, the first major deadline of a timetable set out by the Security Council.
Ban said Damascus has extended "consistent, constructive" support to the mission but warned "the job is far from complete and much important work remains to be done."
"Without sustained genuine commitment by the Syrian authorities, the joint mission will not fulfil its objectives," he said.
On the battlefield, Kurdish fighters advanced across the northeast after seizing an Iraqi border post from jihadists over the weekend, according to the Syrian Observatory for Human Rights, a Britain-based group.
It said the Kurds had seized two villages in Hasakeh province and surrounded a rebel brigade that is part of the Western-backed Free Syrian Army, forcing it to surrender a tank, rocket launchers and vehicle-mounted canons and heavy machine guns.
As the conflict has grown increasingly muddled, the Kurds have fought both the army and other rebel groups in a bid to carve out an autonomous zone modelled on the Kurdish region of Iraq.
Jihadists from the Islamic State of Iraq and the Levant have meanwhile sought control over the border to facilitate the flow of fighters and arms, as it has launched attacks in both Iraq and Syria.