"Iran, Russia and Turkey as the guarantors of Astana Process are working to strengthen Syrian-Syrian dialogues and help Syrian people decide about their future," Mousavi said on Sunday.
The Iranian foreign ministry spokesman reiterated that the three countries will achieve their goal by setting up de-escalation zones, establishing Constitution Committee and pursuing the process of dialogue and national reconciliation.
Mousavi, meantime, dismissed claims of some media outlets about the decision of the guarantor states on the Astana Process regarding the future of the Syrian government, describing it as "baseless".
The spokesman reiterated the Syrian people are the only ones to decide about their future, the type of government and their rulers, and said that Iran has always stood by the Syrian government and people to fight terrorism and will continue to do so in future.
In relevant remarks on April 19, Iranian Foreign Minister Mohammad Javad Zarif met and conferred with his Syrian counterpart Walid Al-Muallem in Damascus with a focus on combat against terrorism.
During the meeting, the two foreign ministers discussed the latest developments in Syria, the political process, the fight against terrorism and regional issues.
During the one-day visit, Zarif also met and held talks with Syrian President Bashar al-Assad on bilateral relations, regional developments and Syria's political issues in the fight against terrorism.
Meanwhile, in his last visit to Syria on April 16, 2019, Zarif lauded the resistance of the people and government of the Arab country against terrorism, highlighting that Syrians saved the whole region from ISIL's expansion in West Asia.
Resistance of government and people of Syria against the threat of terrorism saved the people of this region from a big danger and conspiracy, Zarif said.
The Iranian foreign minister stressed the need for expelling all terrorists from Syria and respecting the country's sovereignty and territorial integrity.