Russian president Vladimir Putin has ordered the start of Russian troops' withdrawal from Syria.
r Putin made the announcement after a meeting with Russian Defense Minister Sergey Shoigu and Foreign Minister Sergey Lavrov. He said the pullout will start from Tuesday.
Mr Putin said: "I consider the objectives that have been set for the Defense Ministry to be generally accomplished.
"That is why I order to start withdrawal of the main part of our military group from the territory of the Syrian Arab Republic starting from tomorrow."
The Russian president said the Russian airbase in Hemeimeem in Syria's coastal province of Latakia and a naval facility in the Syrian port of Tartous will continue to operate.
A Kremlin spokesman said Mr Putin had telephoned Syrian president Bashar Al Assad to inform him of the Russian decision.
Russia entered the civil war in September last year and has been conducting airstrikes against Isis and other militant groups.
Mr Putin did not specify how many planes and troops should be withdrawn. The number of Russian soldiers in Syria has not been revealed.
The UN special envoy for Syria, Staffan de Mistura, who restarted peace talks between the Syrian government and the opposition in Geneva on Monday, said he had no comment on Mr Putin's announcement when contacted by The Associated Press.
Earlier in the day, he warned that the only alternative to the negotiations is a return to war, and described political transition in the country as "the mother of all issues".
The Russian and US-brokered ceasefire that began on February 27 has largely held, but both the Syrian government and its foes have accused one another of violations. The Islamic State group and al Qaida's branch in Syria, the Nusra Front, are excluded from the ceasefire.
Mr Putin said the move would send a "good signal" to the parties to the conflict, help raise trust and help serve as a stimulus for Syria's political talks. The Kremlin said the president coordinated the move with Assad.
Mr Putin added that the Russian troops will continue to oversee the observance of the ceasefire.
Moments before meeting with a Syrian government envoy, in Geneva, Mr de Mistura laid out both high stakes and low expectations for what is shaping up as the most promising initiative in years to end the conflict that moves into its sixth year on Tuesday. At least a quarter of a million people have been killed and half of Syria's population has been displaced, flooding Europe with refugees.
The Geneva talks come as the truce helped vastly reduce the bloodshed and allowed the recent resumption of humanitarian aid deliveries to thousands of Syrians in "besieged areas" - zones surrounded by fighters and generally cut off from the outside world.
Mr de Mistura laid out a stark choice for Syrian parties in the talks, saying: "As far as I know, the only plan B available is return to war - and to even worse war than we had so far."
The two sides are deeply split on Assad's future. His foreign minister, Walid al-Moallem, said that any talk of removing Assad during a transitional period sought by the UN is "a red line", and rejected the international call for a presidential election to be held within 18 months - a key demand of the opposition.
But Mr de Mistura, keeping to language laid out in the UN Security Council resolution in December that paved the way for the talks, insisted that political change, including a timetable for new elections within 18 months, is the ultimate goal.
"What is the real issue - the mother of all issues? Political transition," he said.
Assad, however, has announced that parliament elections in Syria will go ahead next month according to schedule. A Syrian official, Hisham al-Shaar, said the elections will be held only in areas under government control and there will be no polling stations in Syrian embassies abroad or in refugee camps.
On Monday, as the election campaign officially kicked off, streets in the capital Damascus were festooned with electoral banners and posters of hundreds of government-approved candidates.
In the so-called proximity talks, the two sides do not meet face-to-face, but meet separately with Mr de Mistura and his team, who shuttle back and forth.
The talks began on Monday with Mr de Mistura hosting a government delegation led by Syria's UN ambassador, Bashar Ja'afari. Speaking to reporters afterwards, Mr Ja'afari called the meeting "positive and constructive" and said the government delegation "submitted ideas and views" for a political solution to the crisis. He said the opposition will meet Mr de Mistura on Tuesday, and his delegation would meet again on Wednesday.
Syria's state news agency quoted Assad as saying that the Russian military will draw down its air force contingent from Syria but will not leave the country altogether.
State TV also quoted Assad as saying Russia will decrease its presence to levels "in line with the situation on the ground and the continuation of the cessation of hostilities".
Assad said the collaboration between Russian and Syrian forces has secured "victories against terrorism and returned security to the country".