From the perspective of the German and Japanese governments, the Lend-Lease Act was a major threat. It meant that the United States, which had previously been neutral in World War II, was now actively supporting the Allied cause. This made it much more difficult for Germany and Japan to win the war. In addition, the Lend-Lease Act allowed the United States to build up its own military strength, which further threatened Germany and Japan.
As a result, the German and Japanese governments did everything they could to try to prevent the passage of the Lend-Lease Act. They lobbied the United States Congress, and they even threatened to declare war on the United States if the act was passed. However, their efforts were unsuccessful, and the Lend-Lease Act was passed on March 11, 1941.