Slovenia on Thursday imposed sanctions and barred Bosnian Serb leader Milorad Dodik, a pro-Russian separatist, from entering the European Union country.
Slovenia is the latest European Union member state to impose a travel ban on Dodik, following similar moves by Germany, Austria, Lithuania and Poland earlier this year.
The Slovenian government's decision followed Dodik's refusal to step down from the position of the president of the Serb Republic, or Republika Srpska (RS), despite a court ruling that removed him from office.
In August, Dodik was formally ousted by Bosnia's electoral authorities after he was sentenced to a year in prison and banned from politics for six years for flouting decisions made by the international envoy in charge of the peace deal that ended the 1990s war.
Dodik, who travelled to Russia this week, has routinely challenged the envoy and repeatedly called for the separation of the Serb-run half of Bosnia to join Serbia, which has prompted U.S. sanctions against himself and his close associates and family.
However, he remains deeply entrenched in power. Dodik also retaliated with a series of controversial laws, which were later struck down by the courts, including one that barred Bosnian federal police and the judiciary from the RS.
Slovenian media have reported that Dodik's family owns a number of properties in the country, including villas on the Adriatic Sea coast.
"The government unanimously decided to ban Milorad Dodik from entering Slovenia," Deputy Prime Minister Matej Arcon told a news conference on Thursday.
Arcon however said he could not disclose the reasons for the travel ban, adding they were declared "confidential."
There were no immediate reports that Dodik has tried to enter Slovenia recently.
According to private news website N1, quoting unnamed sources, a key argument for imposing the ban was the discovery of alleged "capital transfers" by Dodik and his allies from the Bosnian entity to Slovenia.
The United States played a key role in brokering a peace agreement that ended Bosnia's 1992-95 bloody ethnic war that killed 100,000 people and displaced millions.
Dodik's policies are widely seen as undermining the tense peace in Bosnia between the country's three ethnic groups – Bosniaks, who are mainly Muslim, Serbs and Croats.
Slovenia declared independence from former Yugoslavia – which also included Bosnia – in 1991, and was the first former Yugoslav state to join the EU and NATO in 2004.
Russia and neighboring Serbia have supported Dodik in his rejection of the decisions to remove him from office, calling them anti-Serb.
The Dayton peace accords for Bosnia allowed for the creation of the Serb-run and Bosniak-Croat entities, bound by joint central institutions.
There have been fears that Moscow could help stir instability in Bosnia and the Balkans to avert some of the attention from the war in Ukraine.