The United States on Wednesday imposed fresh sanctions on Bosnian Serb leader Milorad Dodik, who aims to take the Serb Republic out of Bosnia’s armed forces, accusing him of corruption and threatening the stability and territorial integrity of Bosnia and Herzegovina.

The U.S. Treasury Department in a statement said it also slapped sanctions on media outlet Alternativna Televizija d.o.o. Banja Luka, accusing Dodik of acquiring it to further his own agenda and exerting personal control over it.

The designations are the first use of an executive order issued in June allowing the United States to target those threatening peace or stability in the Western Balkans.

Bosnia is experiencing its gravest political crisis since the end of the war in the 1990s, reviving fears of a break-up after Bosnian Serbs blocked the work of the central government and Serb lawmakers voted to start pulling the autonomous Serb Republic out of state institutions.

“Milorad Dodik’s destabilizing corrupt activities and attempts to dismantle the Dayton Peace Accords, motivated by his own self-interest, threaten the stability of Bosnia and Herzegovina and the entire region,” Brian Nelson, Treasury’s under secretary for terrorism and financial intelligence, said in the statement.

The U.S.-brokered Dayton peace agreement in 1995 ended three-and-a-half years of ethnic warfare in Bosnia. Some 100,000 people were killed in the conflict and 2 million forced from their homes.