After defeating Willkie, Roosevelt won congressional approval of the Lend-Lease program, which was designed to aid the United Kingdom in its war against Nazi Germany. After Germany began war against the Soviet Union, Roosevelt extended Lend-Lease to the Soviet Union as well. In Asia, Roosevelt provided aid to the Republic of China, which was resisting an invasion by the Empire of Japan. In response to the July 1941 Japanese occupation of French Indochina, Roosevelt expanded a trade embargo on Japan to cut off oil that Japan urgently needed for its fleet. After attempting to re-open oil exports, Japan launched an attack on the U.S. fleet stationed at Pearl Harbor. In response, Congress declared war on Japan and, a few days later, on Germany and Italy. Along with Britain and the Soviet Union, the United States became a leading member of the Allied Powers. The U.S. funded much of the war efforts of the other allies, and supplied munitions, food and oil. In consultation his Army and Navy officials and British Prime Minister Winston Churchill, Roosevelt decided on a Europe first strategy, which focused on defeating Germany before Japan. In practice, however, in 1942 and 1943 the U.S. focused on fighting Japan.