The opposition factions so far have struggled to form joint delegation to attend the talks.
UN Special Envoy for Syria Staffan de Mistura said on Tuesday he would select the delegates for Geneva talks himself if a united Syrian opposition delegation is not formed by February 8.
"No invitation to peace talks could be accepted if their outcome is not aimed at the full transition of power to an interim government," the opposition said in its Twitter blog.
The armed opposition also demanded the release of all prisoners by Damascus as a precondition for resumption of peace talks in the war-torn country.
"No steps could be taken toward a political solution without a fully-enforced ceasefire and respective monitoring mechanisms…these steps also include the release of prisoners, women and children in the first place," the opposition tweeted.
