The envoy's statement took special aim at moves made by the Serb-dominated statelet on Thursday evening, when its legislature passed a raft of laws to prohibit the national police from operating on its territory and rejected jurisdiction from its central courts. 

"These actions by the ruling coalition in Republika Srpska seek to destabilise the institutions exercising constitutional responsibilities of the State," the statement added. 

The remarks come days after Bosnian Serb leader Milorad Dodik was convicted in a landmark trial for defying rulings made by Schmidt, who oversees the Dayton accords that ended the 1992-95 intercommunal war in Bosnia, which claimed almost 100,000 lives.

The case against Dodik has been widely seen as a test of the divided Balkan nation's weak central government after the 65-year old RS president was accused of flouting the country's peace deal.

The Dayton accords split Bosnia into autonomous halves -- a Muslim-Croat federation and the Serb-dominated RS -- connected by a central government under the supervision of the high representative.

The high representative holds vast powers in Bosnia -- including the ability to effectively fire political leaders and strip them of power.

The RS president has repeatedly threatened to pull the Serb statelet out of Bosnia's central institutions -- including its army, judiciary and tax system, which has led to sanctions from the United States. 

Denis Becirovic -- the Bosnian Muslim member of the tripartite presidency -- slammed Dodik and RS officials, saying their moves were an "attack on the country's constitutional order".