"The two co-chairs each submitted a proposal for the agenda and these were exchanged. There is not yet agreement on the agenda and discussions are continuing," Jenifer Fenton, the spokeswoman for UN Syria envoy Geir Pedersen, told dpa.
The goal of the negotiations has been to build momentum towards a political solution to Syria's bloody civil war, which has lasted nearly nine years.
Talks started in October with 150 delegates representing the government, opposition and civil society in equal parts. Work on the constitution is to be carried out by a smaller drafting committee consisting of 15 delegates from each of those three branches.
Opposition spokesman Ibrahim Jabawi accused the government of blocking the committee's talks.
"We all know the regime delegation: They want to obstruct talks for the sake of obstructing, ... they do not want a political solution, ... so they invent excuses and reasons to put up obstacles," Ibrahim Jabawi, a member of the opposition delegation, told dpa.
Mais al-Kridi, who represents Syrian civil society on the committee, confirmed that "there has been no agreement on the agenda."
Al-Kridi stressed that the negotiations will continue, even if they are facing some obstacles.
UN Secretary General Antonio Guterres has expressed hope that the Geneva talks could lead to a broader peace process to end the war.  
-----------------------------------------------------------------------------------------------------------------