During Kostov's trial for treason, American Minister Heath was frequently mentioned as a contact of Kostov. He was blamed for Kostov's alleged plot to overthrow the Bulgarian government, and for using the American Legation as a center of espionage. The United States responded to these charges by breaking diplomatic relations with Bulgaria on February 22. Heath and the forty-three members of the U.S. legation boarded the Orient Express on February 23 and left for Turkey. The Bulgarian Government denounced the break in relations as a new stage in "the fight of the American imperialists against the front of peace and democracy." Thereafter the Polish Embassy in Washington looked after Bulgarian interests in the United States, and the Swiss Embassy in Sofia protected American interests in Bulgaria.