(Reuters) – Europe and the United States teamed up on Tuesday to press Bosnia, Serbia and Kosovo to overcome the legacy of Yugoslavia’s bloody collapse as a condition of closer integration with the West.

“If you do not make progress you will be left behind,” U.S. Secretary of State Hillary Clinton warned at the start of a trip to the region with EU foreign policy chief Catherine Ashton.

NATO member Croatia will follow Slovenia in joining the 27-nation EU next year, but accession is a very distant prospect for the other five countries carved from federal Yugoslavia in the 1990s.

In Bosnia, where 100,000 people died in a 1992-95 war, Clinton urged rival Serb, Muslim and Croat leaders to overcome ethnic infighting that has stalled reforms sought by the EU and NATO, “for the sake of the young people of this country”.