“After the visit I made to Damascus, there is agreement from the Syrian government for a ceasefire during the Eid,” Brahimi told reporters in Cairo on Wednesday.
Damascus will announce the decision on Wednesday or Thursday, the UN envoy added without giving any precise time period for the ceasefire.
The Eid al-Adha holiday starts on Friday and will continue for four days.
“Other factions in Syria that we were able to contact, heads of fighting groups, most of them also agree on the principle of the ceasefire,” he added.
However, insurgents fighting the Syrian government say they will accept a ceasefire only if the government forces hold fire first.
“If this humble initiative succeeds, we hope that we can build on it in order to discuss a longer and more effective ceasefire and this has to be part of a comprehensive political process,” Brahimi noted.
The UN envoy proposed the temporary ceasefire between the Syrian government forces and the insurgents during the four-day Muslim holiday of Eid al-Adha (Feast of Sacrifice) starting on October 26.
Brahimi met with Syrian President Bashar al-Assad in Damascus on Sunday following his week-long regional tour aimed at finding a solution to the unrest in Syria.
The heads of the Arab League and the United Nations also issued a joint call to the parties involved in the unrest in Syria, urging them to observe the truce.
The Syrian government had earlier declared that it would support the truce proposal only if the Western countries and their regional allies stopped supporting and financing the insurgents.
Syria has been experiencing unrest since March 2011. The Syrian government holds some Western countries and their regional allies, including Saudi Arabia, Qatar and Turkey, responsible for arming and funding the opposition and foreign insurgents.