The U.N. envoy to Libya is cautiously optimistic that candidates to run a government uniting all the country's political factions could be named this week.

Envoy Bernardino Leon said Monday in Brussels that "there is a chance that we can make progress and have the first names for a unity government this week."

He warned against expectations that are "too high, bearing in mind how difficult the situation is on the ground."

Leon's remarks came during a break in talks involving Libya's mayors aimed at setting up zones for providing humanitarian aid and basic services as well as sending a message of peace.

Libya has two parliaments and two governments, along with rival militaries and militias. The power struggle and fierce fighting have plunged the country into chaos.