The United States provided minor support to China in its fight against Imperial Japan's invasion. It imposed an embargo on the sale of oil to Japan after less aggressive forms of economic sanctions failed to halt Japanese advances. On 7 December 1941 (Honolulu time), Japan entered World War II with the Japanese occupation of Malaya, as well as other attacks including attacking the U.S. naval base at Pearl Harbor and American-ruled Philippines, and the Japanese invasion of Thailand.