The Syrian government is expected to announce Thursday its decision about taking part in a cease-fire during the Eid al-Adha holiday, which begins in the evening.
The foreign ministry said Wednesday that the government was still weighing whether it would participate in the truce.
Those comments followed an announcement by U.N.-Arab League envoy Lakhdar Brahimi, who said Syria and some rebel groups opposed to President Bashar al-Assad had agreed to halt fighting during the holiday.
Brahimi said he hopes a multi-day cease-fire will lead to a longer truce as part of a political process.
He later told the U.N. Security Council there is no quick solution to the fighting, and warned that another failure to break the violence would worsen the 19-month conflict and extend it to other countries.
The Security Council expressed support for the cease-fire and asked regional and international powers to "use their influence" to see that it takes effect.
A cease-fire deal brokered by Brahimi's predecessor as special envoy, former U.N. chief Kofi Annan, fell apart shortly after it took effect in April.
Opposition activists reported shelling by government forces Thursday near Damascus, as well as clashes between rebels and the army in Deraa province.
U.N. peacekeeping chief Herve Ladsous said Monday he was making preparations for a Syria peacekeeping force if a cease-fire takes hold.
Meanwhile, U.N. human rights investigators said Thursday they want to meet with Assad as part of their probe into possible rights violations committed in Syria.