ASTANA, Kazakhstan — Delegates from Russia, Turkey and Iran held hourslong talks in Kazakhstan Sunday on the eve of negotiations between Syrian rebels and President Bashar Assad’s government, trying to forge common ground that would nudge forward a political settlement for the country’s civil war.

The talks between the two warring sides are the first in a year, and are meant as a first step to consolidate a cease-fire reached last month.

Whether Russia and Turkey will manage to bolster the cease-fire they brokered on Dec. 30 will be a key measure of success for the Astana meetings, Syrian opposition spokesman Yahya al-Aridi told reporters in the Kazakh capital Sunday.

The opposition delegation, which arrived in Astana earlier in the day, is made up of about a dozen rebel figures led by Mohammad Alloush, of the powerful Army of Islam rebel group. The Syrian government is sending its U.N. ambassador, Bashar Ja’afari, and military delegates.

The U.N.’s Syria envoy, Staffan de Mistura, is participating in the talks, which are to be followed by more political talks in February in Geneva. The new U.S. administration is not directly involved, because of the “immediate demands of the transition,” the State Department said Saturday, but Washington will be represented by the U.S. ambassador to Kazakhstan, George Krol.