When the Bosnian War broke out in 1992, Ljujić-Mijatović rejected Serb nationalist politics, stayed in Sarajevo during the siege of the city by the Bosnian Serb army, and supported the preservation of a multiethnic Bosnia and Herzegovina. When Nenad Kecmanović resigned his post as Serb member of the Presidency of Bosnia and Herzegovina in July 1992, Ljujić-Mijatović was the Serb delegate with most votes in the 1990 general election who was still residing in the government-controlled territory. Biljana Plavšić and Nikola Koljević had also resigned, and two delegates ahead of Ljujić-Mijatović left the country. She duly took her seat in the Presidency, as the only woman among the seven members. In 1993, Ljujić-Mijatović gave an interview in Vienna about the life in besieged Sarajevo, which prompted Alois Mock, the Austrian Minister of Foreign Affairs, to request that she be named Bosnian ambassador to the United Nations. During the Dayton negotiations, Ljujić-Mijatović resolutely opposed the division of Bosnia and Herzegovina.