Russia's defence ministry has announced that the first of its aircraft has departed Syria following the surprise pullout order from President Vladimir Putin.
The statement came just hours after Putin announced the withdrawal of most Russian forces from Syria, timing his move to coincide with the resumption of Syria peace talks in Geneva.
The start of the negotiations in Switzerland on Monday offered Putin an opportune moment to declare an official end to the five-and-a-half-month Russian air campaign.
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The Russian involvement has allowed Syrian President Bashar al-Assad's army to win back key ground and strengthen his positions before the talks.
Russia did not indicate when the first planes were scheduled to leave, nor how many aircraft and troops would be withdrawn.
The number of Russian soldiers in Syria has never been revealed, but US estimates suggest it varies from 3,000 to 6,000 military personnel on the ground.
Putin made it clear that Russia will maintain its airbase and a naval facility in Syria and keep some troops there.
Syria's state news agency also quoted Assad as saying that the Russian military will draw down its air force contingent but won't leave the country altogether.
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Al Jazeera's Zeina Khodr said Russia's move should be viewed as a message to the West that it does not want open-ended involvement in the five-year conflict.
But she noted that Russia's military presence remains significant.
"We have to remember this is not an end to the military presence. The fact the S-400 defence system is still on the ground means Russia is still the main external player in Syria," she said.
Assad's office said he and Putin spoke on the phone on Monday and jointly agreed that Russia would scale back its forces in Syria.
It rejected speculation that the decision reflected a rift between the allies, and said that the decision highlighted the "successes" the two armies have achieved during fighting in Syria and restoring peace to key areas of the country.
Putin said on Monday that he hoped the withdrawal of Russian troops from Tuesday would be a stimulus for a political resolution of the conflict.
"I hope today's decision will be a good signal for all conflicting parties. I hope it will sizeably increase trust of all participants in the process," he said.
Russian forces have killed more than 2,000 rebel fighters, including 17 rebel leaders, since the start of the operation in late September.
Those Russian soldiers who stay in Syria will be engaged in monitoring the ceasefire regime, Putin said.
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Donald Jensen, a former US diplomat who worked in Moscow, told Al Jazeera that despite the pullout announcement, Russia still fully backs its ally Assad.
"I think Russia is committed to keeping him in power. There are conceivably circumstances where they'd throw him under the bus. But in their own mind they are fighting for a principle, which is the sovereignty of nation states from outside intervention.
"However, I think this action is also sending a message to Assad that 'you still depend on us', and I don't think the Russians have been particularly happy with Assad's reluctance to talk to the opposition."
The Syrian conflict has killed more than 250,000 people and displaced almost half the country's prewar population of 23 million since it began in March 2011.
A fragile ceasefire has largely held since February 27, and humanitarian aid deliveries have resumed in recent weeks.
Source: Al Jazeera and agencies