A decision by Bosnia's Muslim leader to revive a wartime genocide lawsuit against Serbia at the United Nations' top court has rekindled divisions that led to the 1992-95 war, the top leaders of Serbia and Bosnian Serbs warned on Wednesday.

The bid to appeal a 2007 ruling by the International Court of Justice that cleared Serbia of committing genocide in Bosnia, also dealt a major blow to postwar reconciliation and Bosnia's survival as a multi-ethnic state, Serb officials said.

"Our relations have been pushed backward 25 or 22 years," Serbian Prime Minister Aleksandar Vucic said. "The little trust we built over the years ... is now gone."

Bakir Izetbegovic, the Muslim Bosniak member of Bosnia's tripartite presidency, has initiated the appeal despite a lack of consent from his Croat and Serb counterparts in the presidency.

"Izetbegovic closed the door for Bosnia and its perspective and switched the lights off," said Milorad Dodik, the president of Republika Srpska, the Serb mini-state within Bosnia.

Bosnian Serb leaders have threatened to walk out of joint Bosnian institutions in protest, which would further fuel tensions in the fragile, ethnically divided state.