PARIS — After months of difficult negotiations, Serbia and Kosovo reached an agreement on Friday aimed at overcoming ethnic enmities in Kosovo, a former Serbian province. It is a milestone that officials hope will enhance stability in the region and clear a path for both countries to join the European Union.

Catherine Ashton, the European Union’s foreign policy chief, told reporters that the prime ministers of the two countries had initialed an agreement during talks in Brussels. “It is very important that now what we are seeing is a step away from the past and, for both of them, a step closer to Europe,” she said.

Serbian officials said the accord was subject to approval by “state bodies” in Belgrade, the Serbian capital. But European officials said it was unlikely that Serbia would backtrack.

The European Union is scheduled to meet Monday in Brussels to decide whether to allow Serbia to start negotiations for entry into the group, and analysts said the accord was likely to swing the decision in Serbia’s favor.