Russia said on May 1 that talks are under way to include Syria's Aleppo province in a temporary cease-fire.
"At present, there is an active negotiation process taking place to establish a regime of calm also in Aleppo Province," said General Sergei Kuralenko, the head of Russia's cease-fire monitoring center in Syria.
His comments indicated a shift in Moscow's position a day after Russia said it would not urge Syrian President Bashar al-Assad's forces to halt aerial bombings on Aleppo, saying they were targeting jihadist groups not covered by the cease-fire that took effect in late February.
More than a week of fighting in Aleppo has killed several hundred civilians and darkened the prospects of a UN-backed peace process.
The Syrian army announced a "regime of calm" late on April 29 in the province of Latakia and the Damascus suburbs.
Aleppo, Syria's largest city, was excluded from the plan, and heavy fighting continued in the city.
The Syrian army confirmed a Russian announcement on May 1 that a "regime of calm" around Damascus has been extended for another 24 hours, but did not mention Aleppo, state television reported.
U.S. Secretary of State John Kerry was to arrive in Geneva on May 1 to discuss Syria with his counterparts from Jordan and Saudi Arabia, and with Staffan de Mistura, the UN special envoy for Syria. Russian Foreign Minister Sergei Lavrov was not expected to be in Geneva.
In separate April 30 calls to De Mistura and the lead Syrian opposition negotiator, Kerry voiced "deep concern" about Aleppo. He made clear that ending the violence in the war-ravaged city is a priority, State Department spokesman John Kirby said.