After shakedown out of Norfolk, Va., "Mellena" carried cargo via Guantanamo Bay and Panama to Pearl Harbor where she arrived in mid–March. She trained in Hawaiian waters until 8 April; and following a cargo run to San Francisco and back continued amphibious support training exercises until sailing for the Philippines 13 June. She reached Guiuan, Samar, 28 June. During the closing weeks of fighting in the western Pacific, she made cargo runs to the Palaus, the Admiralties, and the Marianas, and at the cessation of hostilities she was anchored at Iwo Jima. After transporting Seabees to Saipan, she returned to Leyte Gulf 28 August to carry occupation troops to Japan.