In a surprise move, President Vladimir Putin has instructed Russia’s armed forces to start pulling out of Syria.
Putin told Defense Minister Sergei Shoigu on March 14 that Russian military forces had largely fulfilled their objectives in Syria.
"I am therefore ordering the defense minister, from tomorrow, to start the withdrawal of the main part of our military contingent” from Syria, he added.
In a statement on March 15, the Russian Defense Ministry said: "Technicians at the air base have begun preparing aircraft for long-range flights to air bases in the Russian Federation."
Speaking on March 14, the day UN-brokered talks between the warring sides in Syria resumed in Geneva, Putin expressed hope that the withdrawal of Russian troops will be a stimulus for a political resolution of the conflict.
Russia has more than 50 jets and helicopters in Syria and a small ground component protecting them, along with a number of advisers and special forces operating with the Syrian military.
The Russian leader said Russian forces would stay on at the Mediterranean naval base at Tartus and at the Hmeimim air base in Latakia Province, from which Russia has launched most of its air strikes.
The Syrian presidency said President Bashar al-Assad and Putin agreed the Russian move in a telephone call. It also said Russia had pledged to continue its support for Syria in "combating terrorism."
Meanwhile, Syria's army said it will continue to combat the Islamic State militant group, the Al-Nusra Front, and "other terrorist groups linked to them."
A statement issued by the military command said the armed forces would fight in coordination with "friends and allies" until security and stability were restored "to every inch of national territory."
Syria's opposition cautiously welcomed the Russian announcement.
"If there is seriousness in implementing the withdrawal, it will give the [peace] talks a positive push," said Salim al-Muslat, spokesman for the opposition High Negotiations Committee.
"If this is a serious step, it will form a major element of pressure on the regime, because the Russian support prolonged the regime,” Muslat added.
The president of the UN Security Council said all 15 members view the partial Russian withdrawal as "positive."
Angola's UN Ambassador Ismael Gaspar Martins said he sees "a mood" in the council toward "a more positive outcome" in Syria.
"When we see forces withdrawing it means war is taking a different step, so that's good," he said.
British Foreign Secretary Philip Hammond said on Twitter that the "Russian move could be positive if part of real commitment to a Syrian-led political transition and continuation of cessation of hostilities."
German Foreign Minister Frank-Walter Steinmeier said the withdrawal of Moscow's forces from Syria will increase the pressure on Assad to negotiate a "political transition."
The White House said Putin and U.S. President Barack Obama in a phone conversation discussed Russia's partial withdrawal from Syria and the next steps required to fully implement the cessation of hostilities.
Putin ordered the launch of air strikes against "terrorists" in Syria more than five months ago, a move that helped to shore up Assad.
The United States and other Western countries maintain that the Russian air strikes have mostly struck Syrian antigovernment rebel targets and not Islamic State, which Russia has claimed to be targeting.
In an interview with the French newspaper Le Figaro on March 14, Defense Minister Jean-Yves Le Drian said Russia had all but stopped hitting moderate rebels.
The talks in Geneva are aimed at capitalizing on a shaky truce between Syrian government forces and opposition fighters.
The UN special envoy for Syria, Staffan de Mistura, said a resumption of peace talks is a "moment of truth" and insisted the "only Plan B available is return to war."
De Mistura, speaking to reporters moments before resuming talks in Geneva, added that agreeing on political transition in Syria is the "mother of all issues."
The long-awaited talks, which opened on the eve of the fifth anniversary of the outbreak of the conflict, mark the latest bid to end the bloodshed that has killed more than 270,000 people and displaced millions.