Syrian rebel groups said on Wednesday they would not take part in peace talks scheduled this month unless humanitarian articles in the latest UN resolution were implemented.
The groups, which include the powerful Islam Army, mentioned articles 12 and 13 of a resolution that was passed late last year, which calls on the sides in Syria's civil war to allow humanitarian access to all in need and cease attacks on civilians.
"We consider that implementing these articles is self-evident and a human right," they said in a statement.
"We do not accept any compromise on it under any justification or circumstances."
They also called on an opposition council set up to oversee negotiations, expected to start on Jan. 25 in Geneva, "to be steadfast in its honorable position in refusing to enter into any political solutions imposed through massacres".
Last week the groups said in a statement they were under international pressure to make concessions that would prolong the country's five-year-old conflict.
The opposition council told U.N. envoy Staffan de Mistura that the Syrian government had to take goodwill steps, including a prisoner release, before they would go to negotiations.