Syria’s government and opposition groups have agreed to a nationwide cease-fire and are ready to hold peace talks, Russian President Vladimir Putin announced Thursday, raising faint hopes of movement toward a political settlement in the complex, yearslong conflict that has left hundreds of thousands dead and 11 million displaced.

Syria’s military and the Turkish foreign ministry also confirmed the agreement, brokered by Russia, Turkey, and Iran, with the military saying that the deal was being made to pursue a political solution.

The deal – which excludes the jihadi groups ISIS and Jabhat Fateh al-Sham, and all groups linked to them, according to Syria’s military – will go into effect at midnight.

“Reports have just arrived that several hours ago there was a development that we all have looked and worked for for so long,” Putin said at a meeting with Foreign Minister Sergei Lavrov and Defense Minister Sergei Shoigu, according to Russia’s state-run Tass news agency.

Three documents had been signed under the agreement, said Putin: a cease-fire between the Syrian regime and the armed opposition; a package of measures to monitor the cease-fire; and a “declaration of readiness” to commence peace talks.

He said Russia, Turkey, and Iran would act as guarantors of the agreement. The three powers announced their intention earlier this month to broker a solution to Syria’s nearly six-year conflict, sidelining intermittent U.N.-backed efforts, jointly led by Russia and the U.S., which have failed to bear fruit over the years.

Reuters reported that a number of rebel officials had confirmed the deal, although there appeared to be confusion over which groups were included, with several claiming that Jabhat Fateh al-Sham, formerly known as al-Nusra, was a signatory – something Syria’s military denies.

If the cease-fire holds, peace talks between Syria’s government and the opposition will be held in mid-January in Astana, Kazakhstan’s capital.

Previous attempts to impose cease-fires in Syria – which involves persuading the myriad armed groups holding chunks of the country to halt their fighting – have eventually broken down, with the notable exception of a deal brokered in Aleppo earlier this month, after reported mass atrocities caused by airstrikes and blocking of aid deliveries.

The recent agreement allowed for the evacuation of civilians and fighters from the rebel-held eastern districts of the city before Syrian allied forces, including Russia, entered for a decisive victory last week. The recapture of the city has considerably strengthened Syrian President Bashar Assad’s hand, bringing the last of Syria’s five major urban centers back under his control, although rebel groups continue to hold about two-thirds of the country’s territory.

Putin noted that the agreements were “fragile,” and demanded “special attention and assistance with the goal of preservation and development,” Tass reported.

Michael O’Hanlon, a senior fellow at the Brookings Institution, said despite the obstacles faced in imposing the cease-fire, any attempt to halt the fighting had to be welcomed.

“The key point about cease-fires is that they aren’t all black and white – imperfect or partial cease-fires, or even cease-fires observed partly in the breach, can be useful,” he said.

He said that the greatest reason for hope that a cease-fire might take hold in a conflict in which “battle lines are so hardened and hatreds so deep” was that Assad, with Putin’s backing, has “now largely won the war.”

“Perhaps the opposition will recognize its plight and accept a more limited deal,” he said.

According to Reuters, citing sources familiar with Russia’s thinking, the deal proposed by Russia, Turkey, and Iran would see Syria effectively divided into informal zones of influence for each of the troika, with Assad allowed to stay in power until stepping aside at the next presidential elections.

It reported that the deal would allow for regional autonomy for Syria’s various sectarian and ethnic groups within a federal framework controlled by Assad’s Alawite minority.

The deal would require a nationwide cease-fire to be imposed, followed by talks in Astana, before the Gulf states, the United States, and the European Union were gradually brought in – with the Gulf states and the EU potentially earmarked for funding reconstruction efforts. On Thursday, Lavrov said he hoped that U.S. President-elect Donald Trump’s administration would be able to join the talks once Trump takes office next month.

Like previous peace talks and cease-fire deals, the terrorist groups IS and Jabhat Fateh al-Sham would be excluded from any agreement, and operations against them would continue.

Reuters cited Andrey Kortunov – director general of the Russian International Affairs Council, a think tank close to the Russian Foreign Ministry – as saying that reaching a final deal would be hard but that the powers had shifted toward compromise.

One key development was that Turkey – which is on the opposite side of the conflict from Russia and Iran, supporting opposition groups – no longer sought Assad’s removal as a key priority.

“The priority is not Assad, but the territorial integrity of Syria,” Aydin Sezer, co-chair of the Turkey and Russia Centre of Studies, an Ankara-based think tank, told VICE News.

Turkey, facing an insurgency from Kurdish separatists at home, fears that Syrian Kurdish YPG forces – who have been supported by the U.S. in their fight against IS – will establish an autonomous Kurdish statelet on its southern border. The status of Syria’s Kurds will be one of the major question marks for any deal to resolve, although O’Hanlon said he thought a solution could be found.

“If there is a way to ensure that autonomy never translates to independence, then I think it’s possible,” he said.

After nearly six years of grinding conflict that have killed hundreds of thousands of people and displaced 11 million from their homes, no one is under any illusion of an easy fix.

But O’Hanlon said he was “modestly hopeful” about the deal’s potential, noting that the concept was “skeletal and will need to be fleshed out.”

He said that although the opposition had largely lost the war, at least in major urban centers, there was no meaningful incentive for them to stop fighting. As such, any successful agreement would have to offer a degree of self-rule for Sunni and Kurdish areas – as the latest deal’s outline seemed to acknowledge. But it remained to be seen how much autonomy would be offered.

O’Hanlon said he expected any semi-autonomous regions would require monitoring from an international peacekeeping force, as well as their own local political leadership and security forces.

Furthermore, he believed Assad would need to step down from the presidency if he wanted international reconstruction aid from the U.S., Europe, and the Gulf states areas under his control – “though we might be able to tolerate him still ruling parts of the country’s west and main population belts, which could be formed into another autonomous area of sorts.”

“In short, the peace deal needs to find a place for Sunnis to live where they can be safe, and protected from Assad,” he said. “Without that, I don’t see many prospects for success.”

Other potential roadblocks include the role of Iran, which has previously said Saudi Arabia, its regional archrival and a major supporter of Syrian rebel groups, must be excluded from peace talks.

“I am very pessimistic about Iran’s attitude,” said Sezer.

Likewise, Turkish Foreign Minister Mevlut Cavusoglu’s statement Thursday that all foreign fighter groups must leave Syria – including Hezbollah, the Tehran-backed, Lebanese Shia militia that has been a key ally for Assad – highlighted another potential source of tension between the deal’s power brokers.

Sezer said he was not hopeful that the various actors involved in the Syrian quagmire would be able to reach an agreement. “I want to be optimistic about it, but I have doubts,” he said.

In Syria’s rebel-held Idlib province, Zouhir al-Shimale, a freelance journalist who was evacuated from east Aleppo earlier this month, told VICE News that he was hopeful that the cease-fire would result in at least a temporary break in the fighting. “I think it’s going to work maybe, for a while,” he said. “We’ll see if it will last – nothing is sure for us here.”