The clock is ticking to implement a Russian-Turkish deal for the Syrian rebel region of Idlib, but its terms remain hazy and little has changed on the ground. The accord, reached on September 17, aims to stave off a massive regime assault on the last major rebel bastion by creating a 15 to 20 kilometre buffer zone ringing the area. All rebels in the demilitarised zone must withdraw heavy arms by October 10, and radical groups must leave by October 15. But as the deadline draws closer, there has been no indication either condition is being implemented. The main Ankara-backed rebel alliance, the National Liberation Front, cautiously welcomed the agreement but has denied beginning to pull out any of its heavy weapons. And the region's most powerful force, the jihadist-led Hayat Tahrir al-Sham, has yet to announce its stance. "On the ground, essentially, there's no movement. There's no handover of weapons or territory," said Haid Haid, a research fellow at the London-based Chatham House. What is happening, however, is a flurry of negotiations among Russia, Turkey, rebel groups and hardliners to hash out the accord's finer details and bring Idlib's jihadists on board. The thorny questions being discussed include precisely where the buffer would be established, who would patrol it, and whether weapons systems would be simply re-stationed in other rebel zones or handed over to Ankara. Once those stumbling blocks are sorted out, Haid told AFP, implementation can be quick. "In my view, the deal will be implemented on time, but with some amendments," he said. - Devil in the details - The deal was announced in the Russian resort of Sochi after a tete-a-tete between Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan. It was welcomed by world powers, relief agencies and the United Nations, which all hoped it would avert a feared humanitarian catastrophe of unprecedented proportions. But apart from deadlines, very few details were made public. "One possibility is that Turkey and Russia already agreed on all the details but did not announce them," said Haid. "The second possibility is they agreed on the broad outlines without details," allowing Ankara to untangle the knots with Idlib's factions, he said. On Wednesday, Putin said Moscow was still "working in solidarity with Turkey" on Idlib. "We see that they, too, have the most serious attitude towards the deal and are fulfilling their obligations," he said. He spoke hours after Ankara dispatched a new military convoy of vehicles and troops into northern Syria to be stationed at the monitoring posts it already operates in the area. The burden of implementing the agreement has fallen on Turkey, which shares a border with Idlib province and has long backed rebel forces there. The toughest task would be bringing jihadists including HTS, led by former Al-Qaeda members, on board. HTS, jihadists from the Turkestan Islamic Party (TIP) and current Al-Qaeda outfit Hurras al-Deen control more than two-thirds of the planned buffer zone. While Hurras al-Deen has rejected the deal, HTS and TIP have yet to take a position -- which Haid sees as a sign that they could be negotiating with Turkey for better terms. "No news could be more positive than negative," he said. "This area is very important for HTS. It has economic benefits and guarantees the group's sustainability. If it hands over this area, what does it still have?" - 'No progress' - Moscow has accused HTS and other "radical fighters" of trying to torpedo the accord. Foreign ministry spokesman Maria Zakharova said Thursday they "fear finding themselves isolated by the Russian-Turkey deal, and are committing all sorts of provocations and aggravating the situation". Even as it works to persuade heavyweight HTS, Ankara is in talks with other rebel groups on their objections to the deal. After initially welcoming the accord, the NLF refused any Russian presence in the buffer zone, which Putin said would be monitored by Russian military police and Turkish troops. "There's no progress on the deal, except the issue of the patrols. They will only be Turkish," NLF spokesman Naji Mustafa told AFP. "For the demilitarised zone, our heavy weapons aren't in this area anyway," he said. Other rebels fear that the accord could cost them their last major stronghold. Jaish al-Izza, a formerly US-backed faction, rejected the accord on the grounds that it ate away at rebel but not regime territory to create the buffer zone. Damascus, for its part, still hopes to recapture every inch of Syrian territory. In an interview aired Tuesday, Syrian Foreign Minister Walid Muallem said he hoped the deal would prove to be a "step towards the liberation of Idlib."