From London, the Yugoslav government-in-exile supported the struggle of the royalist forces and appointed General Mihailović as Chief Minister of War. However, the importance of the Partisans pushed the allied forces to trust the Communists and give increasingly limited help to Mihailović, who was accused of collaborating with the Axis powers to shoot communist guerrillas. After the Tehran Conference (1943), the Allies finally broke their ties with the Chetniks, forcing the Yugoslav government-in-exile to recognize the preeminence of the Partisans. In June 1944, Prime Minister Ivan Šubašić officially appointed Marshal Tito as the head of the Yugoslav resistance and Mihailović was dismissed. In October 1944, Churchill and Stalin concluded an agreement to split Yugoslavia into two occupation zones, but after the liberation of Belgrade by the Red Army and the Partisans, it became clear the Communists predominated in the country. A harsh treatment, which affected the monarchists, took place; at the request of Churchill, Tito agreed in March 1945 to recognize a Regency Council (which had almost no activity) but opposed the return of King Peter II, who had to remain in exile with Alexandra while a government coalition dominated by the Communists was constituted in Belgrade.