After the German Army invaded the Soviet Union in June 1941, the Soviet leader Joseph Stalin began pressing his new allies for the creation of a in western Europe. In late May 1942 the Soviet Union and the United States made a joint announcement that a "... full understanding was reached with regard to the urgent tasks of creating a second front in Europe in 1942." However, British Prime Minister Winston Churchill persuaded U.S. President Franklin D. Roosevelt to postpone the promised invasion as, even with U.S. help, the Allies did not have adequate forces for such an activity.