The talks, led by EU President Carl Bildt of Sweden, were an attempt to give the central government a stronger role over semi-independent Serbian and Muslim-Croat entities, the EUobserver reported Thursday.
EU and U.S. negotiators tried to convince Bosnian leaders to approve a constitutional reform that would make the state more functional and prepare it for eventual membership in the European Union and NATO, Bildt said. But representatives of the three main ethnic groups -- Serbs, Bosniaks and Croats -- rebuffed the attempts.
"Although some limited progress has been made, further discussions will be required ... and some of the parties will need to demonstrate greater determination and flexibility," Bildt and the U.S. representative, Deputy Secretary of State Jim Steinberg, said in a statement after talks ended Wednesday.
Representatives from the EU and the United States will return to Bosnia next week to resume negotiations.