By the time that Joseph Stalin , Winston Churchill and President Roosevelt met in Yalta in March 1945 , Bulgaria was occupied by the Soviet Army , and a pro-Soviet government had been installed . Bulgaria was discussed only once at Yalta Conference , when British Foreign Secretary Eden said that Soviet-occupied Bulgaria should not be allowed to form an alliance with Yugoslavia , where Marshal Tito was establishing a Communist regime . According to the Minutes of the Conference : " There was an exchange of views between the Foreign Secretaries on the question of the desirability of a Yugoslav-Bulgarian pact of alliance . The question at issue was whether a state still under an armistice regime could be allowed to enter into a treaty with another state . Mr. Eden suggested that the Bulgarian and Yugoslav Governments should be informed that this could not be approved . Mr. Stettinius suggested that the British and American Ambassadors should discuss the matter further with Mr. Molotov in Moscow . Mr. Molotov agreed with the proposal of Mr. Stettinius . " Though the Communist Party formally was only one partner in the new coalition government , they , along with the Soviet representatives , were the real power in Bulgaria . They created a People 's Militia to harass the opposition parties and gradually purged their rivals
Yalta Conference
Yalta Conference
Bulgaria–United States relations