The US military was considering dispatching fighter planes to support the bombing of the Japanese mainland by B-29s. Iwo Jima was the only fighter base. When the mainland bombing of B29 with support fighters is carried out, Japan's ashes will progress at once. Lieutenant General Kuribayashi went to Iwo Jima as the last line of defense for the mainland or to delay the advance of the U.S. forces as much as possible. On February 19, 1945, a landing force of 75,144 U.S. forces, 495 ships, including 17 large aircraft carriers, and a support force of 111,300 personnel arrived at Iwo Jima.