Japan announced declarations of war on the United States and the British Empire later that day (December 8 in Tokyo), but the declarations were not delivered until the following day. The British government declared war on Japan immediately after learning that their territory had also been attacked, while the following day (December 8) the United States Congress declared war on Japan. On December 11, despite the fact they had no formal obligation to do so under the Tripartite Pact with Japan, Germany and Italy each declared war on the U.S., which responded with a declaration of war against Germany and Italy. There were numerous historical precedents for the unannounced military action by Japan, but the lack of any formal warning, particularly while peace negotiations were still apparently ongoing, led President Franklin D. Roosevelt to proclaim December 7, 1941, "a date which will live in infamy". Because the attack happened without a declaration of war and without explicit warning, the attack on Pearl Harbor was later judged in the Tokyo Trials to be a war crime.