(Reuters) -- Syria is prepared for "open battle" against insurgents in the province where Damascus has been allowing them to gather under ceasefire deals, said the government official in charge of negotiations that have seen rebels yield swathes of territory.
The past year has seen President Bashar al-Assad's government recapture many key areas from rebels, including suburbs of the capital in what Damascus calls "reconciliation" deals. Insurgents agree to give up territory in return for safe passage out.
Fighters have been given safe passage to Idlib Province, the biggest remaining rebel stronghold, which is in the northwest of the country. The government has sent buses to take them with their families.
Idlib was also the destination for many of the 35,000 rebel fighters and civilians evacuated from eastern Aleppo last month in a deal brokered by Turkey and Russia, Assad's most powerful ally, after insurgent groups were routed in the city.
Ali Haidar, who as national reconciliation minister has been responsible for negotiating local deals, said he expected more accords in coming months to send thousands of fighters to Idlib from areas near Damascus and south of it, as the army advances.
But in an interview in Damascus, he said the state could not allow Idlib to remain in insurgent hands indefinitely. Unless there was an international deal that addressed the situation, "then the other option is to go to an open battle with them", he said.
"The Syrian state is clear in its policy when it said it will not forego any patch of Syria, and I think Idlib is one of the coming hot areas," Haidar told Reuters.
He said foreign fighters must leave and rebel supply lines via Turkey be cut off.
Allowing fighters who surrender elsewhere to escape to Idlib has emerged as the basic offer on the table wherever government forces have rebel-held areas under siege.
Damascus says its deals permit Syrians to stay as life returns to normal after a ceasefire. The opposition says the deals amount to forced demographic change to drive out Assad's opponents, an aim which the government denies.
Idlib province at the border with Turkey is almost entirely controlled by rebel groups fighting to topple Assad, including powerful Islamist factions such as Ahrar al-Sham and Fateh al-Sham, formally known as the al Qaeda-linked Nusra Front.
Around Damascus, the pace of local deals has picked up in recent months, notably since rebels agreed to leave Daraya southwest of the capital in August for Idlib some 300 km (200 miles) away.
Rebels now face the firepower of an army backed by Russian air support and ground troops from Iran and Lebanon's Hezbollah movement. Haidar said more local deals were being concluded as armed groups found the "horizon" closing in on them.
"The experience of Daraya accelerated the final conviction on the part of the militants that the state cannot be confronted forever," he said.
Haidar said some 10,000 fighters had been given safe passage to Idlib so far from areas other than Aleppo, and he expected about as many more in the next six months "if we complete the reconciliations in the rural Damascus areas, Deraa and Quneitra".
NO DEAL YET FOR DOUMA
Rebels still hold territory in those areas and near Damascus, including Douma in the Eastern Ghouta area.
Haidar said efforts to conclude a reconciliation deal there had yet to yield a result, blaming Saudi Arabia which wields influence over the main rebel group there, Jaish al-Islam.
Saudi Arabia has been one of the main backers of the insurgency against Assad, along with Qatar, Turkey and the United States. In the Damascus area "the problem remains specifically Douma, because everyone knows that there is an armed group in Douma linked with Saudi Arabia", Haidar said.
He also indicated a local deal could be reached soon in the Wadi Barada valley near Damascus, where government forces and their allies are currently battling rebels. A deal could be completed "in a very short period, not months", he said.
Rebel groups have cited the assault on Wadi Barada as proof that the government is not committed to a new ceasefire brokered by Turkey and Russia. The United Nations says it has received reports that the latest fighting has displaced at least 7,000 people from the area where an estimated 45,000 people live.
Syrian rebel groups said on Monday they had decided to freeze any talks about their possible participation in proposed peace talks unless the government and its Iran-backed allies end what the rebels say are truce violations.
Haidar accused Saudi Arabia and Qatar of trying to obstruct the meeting in Kazakhstan's capital Astana. Turkey, on the other hand, was "searching for an exit far removed from its previous Saudi and Qatari allies," he said.
"So far Astana is an expression of positive intentions, and these intentions have not been translated into real actions," he said, though it was possible that a first meeting could still be held there at the end of the month.
Additional reporting by Tom Miles in Geneva; writing by Tom Perry; editing by Peter Graff.