A round of peace talks between Ukrainian and pro-Russian rebel leaders has been scrapped, the host of the negotiations in Minsk, the capital of Belarus, has said.
Dmitry Mironchik, a spokesman for the foreign ministry of Belarus, told the Associated Press that the talks broke down on Friday but did not give a reason.
The opening round was held on Wednesday, one day after Ukraine decided to seek NATO membership. That change of policy added a new element of tension to attempts to resolve the violent crisis in the country.
Negotiators reached a deal on only one item on their agenda: A prisoner swap that will involve 225 rebels and 150 Ukrainian troops. That was the least contentious of four issues under discussion.
This week's talks were meant to reinforce two September agreements that aimed to do two things: end one of Europe's bloodiest recent conflicts and preserve Ukraine as a single nation in which Russian-border regions enjoyed more autonomy. Yet little of what was agreed to in September has been achieved.
An aide to one of the two rebels at Wednesday's negotiations said he was heading back to Donetsk, the separatist region in eastern Ukraine, because there appeared to be little point in staying in Minsk.
The separatist industrial regions of Luhansk and Donetsk staged their own leadership polls in November. That angered Ukraine's government in Kiev and dampened early glimmers of hope that a political settlement might be reached soon.
Meanwhile, insubordinate field commanders from both sides have ignored the formal truce declaration and waged battles that killed 1,300 more people.
United Nations officials fear that their toll of 4,700 deaths in the conflict so far may be too conservative because militias have been hiding their losses and denying access to their burial sites to outside observers.
The most difficult task facing European mediators is finding a way for the sides to begin pulling back their tanks so that an 18.6-mile-wide buffer zone can be established across the war zone.
The rebels' most pressing demand is the resumption of social welfare payments from Kiev, which were suspended last month out of fear that they were being used to finance the revolt.
Al Jazeera and wire services