MINSK, Belarus (AP) — Ukrainian negotiators and Russia-backed separatists on Wednesday agreed on another area to disengage their troops in eastern Ukraine.

The talks of between representatives of Ukraine, the separatists, Russia and the Organization for Security and Cooperation in Europe were held in the Belarusian capital of Minsk.

The negotiators discussed new confidence building measures to pave way for a meeting of the leaders of Russia, Ukraine, France and Germany scheduled for April in Berlin.

During their Dec. 9 talks in Paris, the four leaders made a deal to exchange prisoners and pledged to ensure a lasting cease-fire in fighting between Ukrainian troops and Russia-backed separatists. They made no progress, however, on key contentious issues — a timeline for local elections in eastern Ukraine and when Ukraine can get back control of its borders in the rebel-held region.

The conflict in eastern Ukraine erupted in April 2014 weeks after Russia annexed Ukraine’s Crimean Peninsula. The fighting has killed more than 14,000 and devastated Ukraine’s industrial heartland.

Ukraine and the rebels had pulled back troops and weapons in three areas in preparation for December’s talks in Paris, where the four leaders agreed to pull back troops in three more sectors of the front line to help observe a lasting truce.

On Wednesday, the negotiators chose one location for the troops pullback — the village of Hnutove — but failed to come to terms on two other areas. They also agreed to continue searching for those missing in action.

OSCE envoy Heidi Grau noted that the number of cease-fire violations in eastern Ukraine has increased since the last month. She urged both sides to observe the truce and take stronger efforts to clear land mines.