In July 1903, Baron Burián was appointed by Emperor Franz Joseph I to serve as Joint Finance Minister of Austria-Hungary, replacing the deceased Benjamin Kállay von Nagy-Kálló who had held the post since 1882.

[6] In January 1915, Austro-Hungarian Foreign Minister Count Berchtold was pressured by Germany to make territorial concessions to Italy as the price of securing that country's neutrality.

[7] Baron Burián's name was put forward by Count Tisza, who was a close friend and ally, as Berchtold's successor which was accepted, albeit reluctantly, by Emperor Franz Joseph.

)[11] A relative moderate, he initially resisted German pressure for territorial concessions as the price of maintaining Italy's neutrality, although he somewhat vacillated towards the end as Austro-Hungarian forces suffered a crushing defeat with the surrender of Przemysl in March.

[15] He further angered Germany and its military leaders by proposing a peace plan that called for the re-establishment of a free Belgium and the return of all captured French territory in exchange for recognition of German and Austro-Hungarian rights in Eastern Europe.

Following the Sixtus Affair, the position of Count Czernin had become untenable and on 15 April 1918, Baron Burián was recalled by Emperor Charles I to serve as imperial foreign minister again, with instructions to negotiate an end to the war on favorable terms.

[17] Burián sought a compromise peace settlement, a course he had consistently advocated, but the deteriorating military situation of Austria-Hungary provided him little margin for manoeuvre facing increasing disputes with the German ally.

[24] However, his rigidity and pedantry likely made him a less suitable choice at the helm of Austro-Hungarian diplomacy at such a decisive period as World War I with a greater need for flexibility according to one historian.

"Although he was criticized as being doctrinaire, inflexible, and a Balkanist without a wider purview, Burián had a clear vision to protect Austro-Hungarian prestige, integrity, and power, which he was determined to uphold in face of compounding internal and external pressures.