All parties to the intra-Syrian talks in Astana have confirmed their participation for this week's summit to be held Monday and Tuesday, amid continued fighting in northwestern Syria and south of the capital.
The Kazakh foreign ministry told Russian state media RIA Novosti that delegations from Russia, Iran, and Turkey, in addition to the Syrian government and opposition representations, will participate.
UN Special Envoy to Syria Staffan de Mistura and a delegation from Amman will also observe.
Russia, Iran, and Turkey are the three guarantors of the Astana process.
Nine people were killed on Saturday after an explosion in Idlib, the Syrian Observatory for Human Rights reported. The incident left 26 more wounded.
Opposition groups have been bussed to northern areas of Syria over the past month.
Idlib has been under the control of Hayat Tahrir al-Sham (formerly the Nusra Front), Syria's former al-Qaeda affiliate.
There also have been recent reports of ISIS attacks in southern Damascus.
Multiple Syrian ceasefires implemented through the Astana and UN-backed Geneva processes have not held.
The UN estimates more than 350,000 Syrians have been killed in the conflict that began in 2011. At least half of all Syrians at one time or another have been displaced from their homes.