In a telephone conversation on Thursday, de Mistura pointed to a recent decision by Damascus to accept a ceasefire with opposition groups during the UN-brokered peace talks in Munich and said the truce will begin on Saturday, at midnight.
He further praised Iran’s constructive role in the fight against terrorism and the truce in Syria, saying that all the member counties of the International Syria Support Group have a significant role in maintaining ceasefire in the Arab country.
Earlier this week, the US and Russia agreed on a "cessation of hostilities" between the Syrian government and groups fighting it in a deal that excludes Daesh (ISIL) and the al-Nusra Front.
The Syrian government and the main umbrella for Syrian opposition and rebel groups announced on Tuesday they both conditionally accept the ceasefire.
Syria has been gripped by civil war since March 2011 with various terrorist groups, including Daesh (ISIL), currently controlling parts of it.
Meanwhile, Russia’s recent aerial support for the Syrian forces has given fresh impetus to the fight against the foreign-backed terrorists.
According to a new report by the Syrian Center for Policy Research, the conflict has claimed the lives of over 470,000 people, injured 1.9 million others, and displaced nearly half of the country’s pre-war population of about 23 million within or beyond its borders.