 Roosevelt arrived in Tehran on 27 November 1943 and settled into the American legation.Close to midnight, Vyacheslav Molotov, Stalin's top aide, summoned Archibald Clark-Kerr (the British ambassador in the Soviet Union) and Averell Harriman (the American ambassador in the Soviet Union) to the Soviet embassy, warning them of an assassination plot against Roosevelt, Churchill and Stalin.Molotov informed them several assassins had been apprehended, but reported additional assassins were at large and expressed concerns for President Roosevelt's safety.