Over three decades after proclaiming a so-called republic, Bosnian Serbs, led by their President Milorad Dodik, ignored global condemnation and warnings Tuesday to mark the entity's controversial "national holiday."

Bosnian Serb political leaders, who were hostile to Bosnia's independence from Yugoslavia as sought by Bosniaks and Croats when the communist federation started to collapse in the early 1990s, proclaimed their so-called republic – Republika Srpska – on Jan. 9, 1992.

Three months later an inter-ethnic war broke out in Bosnia, claiming over 100,000 lives.

Since the 1992-1995 war, Bosnia and Herzegovina has been split along ethnic lines into two semi-independent entities – the mostly-Orthodox Christian Serbs' Republika Srpska (RS) and the Federation of Bosnia and Herzegovina, made up of mostly-Muslim Bosniaks and mostly-Catholic Croats.

In 2015, Bosnia's constitutional court ruled that the Jan. 9 holiday discriminates against the country's Bosniaks and Croats.

"We have no intention of insulting anyone, it's not a whim," Dodik told Agence France-Presse (AFP) in an interview Monday.

"We simply have the right to mark the day we consider to be our day."

"Republika Srpska has shown over the years that it can function and exist on its own," he said.

But the Organisation for Security and Cooperation in Europe (OSCE) warned in a statement last week that the "Day of the Republika Srpska" celebration "directly contravenes the constitutions of both Bosnia and Herzegovina and of Republika Srpska."

It also branded the event, celebrated every year by Bosnian Serb leaders with great pomp, as "an act of discrimination."

'Peaceful separation'

Weak central institutions link the two Bosnian entities. Nearly a third of Bosnia's 3.5 million people live in Republika Srpska, whose territory makes up nearly half the Balkan country.

Dodik was among the 83 ethnic Serb lawmakers who decided to create Republika Srpska.

The 64-year-old, who has dominated Bosnian Serb politics since 2006, has little regard for the decisions taken by Bosnia's central institutions and does not recognize the authority of the country's constitutional court.

In recent months, he announced that his entity was on course to organize its own elections and take over state property on its territory.

He also said that Bosnia is moving toward a "peaceful separation."

Dodik, a Kremlin ally, has also hurled insults at the top international envoy to Bosnia, tasked with overseeing the civilian aspects of the Dayton peace deal that ended the 1992-1995 war, and at the U.S. ambassador to the country.

It prompted NATO Secretary-General Jens Stoltenberg to warn in November against "secessionist and divisive rhetoric" and Russia's "malign" interference in Bosnia.

Dodik, who is under U.S. sanctions, is also a close ally of Serbian President Aleksandar Vucic.

He stood next to Vucic when the Serbian leader announced his party's victory in Serbia's parliamentary elections in December, contested by opposition groups.

Serbia supports the "territorial integrity of Bosnia-Herzegovina," but is also "strongly opposing any humiliation of the Republika Srpska," Vucic said Monday in a congratulatory message to Dodik for the Bosnian Serb entity's "holiday."

"I know that you will do your best to preserve regional stability, as this is in the highest interest of our Serbian people," Vucic said.

Show of force

Meanwhile, in an apparent show of force, U.S. special forces and the Bosnian army conducted a bilateral air-to-ground training exercise Monday.

Two F-16 fighter jets flew over Bosnia to underline U.S. support for its territorial integrity against "secessionist activity" by Serbs at odds with the peace accords, the U.S. embassy in Sarajevo said.

An embassy statement referred to renewed separatist agitation by Dodik, who has long called for it to secede and join its neighbouring ally Serbia.

"This bilateral training is an example of advanced military-to-military cooperation that contributes to peace and security in the Western Balkans, as well as demonstrates the United States' commitment to ensuring the territorial integrity of Bosnia-Herzegovina in the face of anti-Dayton and secessionist

activity," the statement said.