President Recep Tayyip Erdogan came home with the Syrian ceasefire he wanted from his meeting with Russia's Vladimir Putin, but the deal leaves key challenges unresolved, not the least the fate of a million displaced civilians still trapped in the warzone.

The deal, announced after six hours of talks between the two leaders in Moscow, also made no mention of the 12 Turkish military posts in the last rebel stronghold of Idlib, most of which now lie in territory seized by the forces of Syrian President Bashar al-Assad after a brutal offensive, backed by Russian air power, in recent months.

Turkey last week declared an official operation against the Syrian regime in Idlib, the last rebel stronghold, after more than 50 of its soldiers were killed in February.

The ceasefire agreed in Moscow pulled all sides back from the brink of a potentially brutal new phase in the nine-year war. But by freezing the frontlines in their current state, the deal effectively allowed the Syrian regime to bank the territorial gains it has made since launching its offensive in December.

Nor did it establish the safe zone that Erdogan has long wanted to protect close to a million people displaced by the Syrian assault, and prevent them flooding over the border into Turkey, which already hosts some four million refugees.

"The agreement is tactical and doesn't totally solve the disagreements between Ankara and Moscow," said analyst Ali Bakeer.

"It is not clear whether Assad will actually pull back under this deal or not, and how the refugees are supposed to go back to their towns if Assad is not going to pull back."

Emre Kaya, of the Edam think-tank in Istanbul, said: "At least for now, the agreement does not meet the Turkish long-term objective of securing a security zone for (internally displaced people) in Idlib.

"Yet, in the short term, as Turkey did not receive the support it expected from its Western allies, to secure a ceasefire is still an acceptable outcome," he added.

In statements to journalists aboard his plane returning from Moscow, Erdogan emphasised the positive aspects of the deal. "The ceasefire gives us important gains in various areas," he said, stressing that it would reinforce Turkey's border "against terrorist and regime attacks".

It also buys Ankara some time to win greater support from the West and its NATO allies, who have so far offered little more than statements of solidarity.

In particular, Erdogan has called for financial support to build new towns in northern Syria to rehouse displaced Syrians.

Assad's assault on Idlib, backed by Russian air power, effectively tore up a previous Turkey-Russia deal signed in Sochi in 2018, which established a no-fire zone in the province overseen by 12 Turkish observation posts. Many believe the latest ceasefire will meet the same fate.

"The Russian agenda remains very clear," a French presidential source said Friday. "That is to retake the entirety of Syria for the regime of Bashar al-Assad."

"This ceasefire is fragile and temporary, because the Syrian regime, supported by the Russians, is determined to retake Idlib and wipe out the jihadists who are there," added Jana Jabbour, a Turkey expert at Sciences Po Paris.

"New battles will take place in Idlib, and they will determine the balance of power between Turks, Russians and the Syrian regime, and their respective influence over discussions on Syria's future politics," she said.

Despite being on opposing sides of the conflict, Moscow and Ankara have kept lines of dialogue open and worked to find a diplomatic solution.

But they are not evenly matched, said Soner Cagaptay, of the Washington Institute for Near East Policy. "The Turkish-Russian relationship is asymmetrical in nature: each time Putin cuts Erdogan a deal, his offer is less favourable than the one before. Today's ceasefire deal is worse than the 2018 Sochi Agreement which it replaces, but it is also better than Putin's next Idlib offer," he said.

Russia and Turkey are keen for the Syrian conflict not to undermine their close ties in other areas, even if it has taken some diplomatic gymnastics to prevent a rupture over the latest clashes in Syria. "They are cooperating in many crucial agendas such as energy. It is the honeymoon that is over, not the relationship," said Kaya, from the Edam think-tank.