Bosnian Serb separatist leader Milorad Dodilk on Thursday warned to block the functioning of Bosnia-Herzegovina's national government unless election regulations enforced by an international envoy are revoked, and Western ambassadors are expelled from the country.

Bosnia's peace overseer, Christian Schmidt, on Tuesday imposed changes to the election law to ensure its integrity through technical improvements after the country's rival ethnic leaders failed to agree on election reform.

Bosnian Serb officials do not recognize Schmidt as the High Representative for Bosnia-Herzegovina, saying the former German government minister was not endorsed by the U.N. Security Council. They have warned that they will not accept his decision and will instead pass their own election law.

Under the Dayton peace accords which ended the Balkan country's war in the 1990s that killed about 100,000 people, Bosnia was split into two autonomous regions – the Serb-dominated Serb Republic and the Federation shared by Bosniaks and Croats.

The High Representative is seen as the ultimate interpreter of the peace accords and has powers to impose laws or sack officials seen as obstructing the peace.

Dodik, a pro-Russian nationalist who was sanctioned by the United States and Britain for obstructing the terms of the peace deal, said that unless Schmidt's decision is annulled within a seven-day period, and declared void by the national parliament, Serb deputies will boycott its work.

It would not be the first time Serb deputies have blocked decision-making in the national government but Bosnia is now hoping to pass reforms needed to open accession negotiations with the European Union following an invitation by EU leaders.

Addressing an emergency session of the Serb Republic's assembly, Dodik said the national parliament should pass election laws and declare itself the only law-making institution, banning the implementation of Schmidt's law.

Ambassadors of the U.S., Britain and Germany, as well as Schmidt, should be declared enemies of Bosnia and expelled from the country, Dodik said, warning that unless his demands are met, his ruling SNSD party will break its partnership with its current partners in the government and block its work.

He also urged the regional parliament to immediately pass a draft election law under which institutions of the Serb Republic would conduct polls in the region by themselves.