The Japanese Imperial Army made a surprise attack on The United States Navy on December 7, 1941 at around 8:00 a.m. The country of Japan and the United States had developed issues with each other throughout the previous decades. Japan decided that an attack on Pearl Harbor, The United States Naval Base, would force The United States to remove economic sanctions that had been placed on Japan for items such as oil. The attacks caused The United States Navy to lose over 20 naval vessels, eight of those being battleships, over 200 airplanes, and over 2,400 navy men. The next day, December 8, 1941, President Roosevelt asked Congress to declare war on Japan. They agreed with his request on the same day. Three days later, Japanese allies, Germany and Italy, declared war on The United States. Shortly after, the United States responded by declaring war on European Forces. This was the United States' official entry into World War II.