Japan launched a surprise attack on the Philippines on December 8, 1941. The Philippine Commonwealth government drafted the Philippine Army into the U.S. Army Forces Far East, which would resist Japanese occupation. Manila was declared an open city to prevent its destruction, and it was occupied by the Japanese on January 2, 1942. Meanwhile, battles against the Japanese continued on the Bataan Peninsula, Corregidor, and Leyte, until the final surrender of United States-Philippine forces on May 1942.