Andrić was appointed Yugoslavia's ambassador to Germany in late March or early April 1939. This appointment, Hawkesworth writes, shows that he was highly regarded by his country's leadership. Yugoslavia's King Alexander had been assassinated in Marseille in 1934. He was succeeded by his ten-year-old son Peter, and a regency council led by Peter's uncle Paul was established to rule in his place until he turned 18. Paul's government established closer economic and political ties with Germany. In March 1941, Yugoslavia signed the Tripartite Pact, pledging support for Germany and Italy. Though the negotiations had occurred behind Andrić's back, in his capacity as ambassador he was obliged to attend the document's signing in Berlin. Andrić had previously been instructed to delay agreeing to the Axis powers' demands for as long as possible. He was highly critical of the move, and on 17 March, wrote to the Ministry of Foreign Affairs asking to be relieved of his duties. Ten days later, a group of pro-Western Royal Yugoslav Air Force officers overthrew the regency and proclaimed Peter of age. This led to a breakdown in relations with Germany and prompted Adolf Hitler to order Yugoslavia's invasion. Given these circumstances, Andrić's position was an extremely difficult one. Nevertheless, he used the little influence he had and attempted unsuccessfully to assist Polish prisoners following the German invasion of Poland in September 1939.