"Centaurus" put to sea from Norfolk, Virginia on 11 December 1943 with cargo for Pearl Harbor, where she arrived 30 December. On 22 January 1944, she cleared with the Southern Attack Force, bound for Kwajalein Atoll in the Marshall Islands, off which she arrived 31 January. During the initial assault, she landed four waves of cargo-laden craft under the protective fire of with a smoothness belying her newness at amphibious warfare, and until 5 February she remained off the atoll landing combat cargo to support troops ashore as they encountered stiffening opposition. She returned to Noumea for training and cargo duty until 31 March, when she sailed from Tulagi to carry men and cargo to Manus and proceeded to Langemak Bay, New Guinea. Here she loaded for the landings on northern New Guinea, and on 15 April put to sea in the second assault echelon for Aitape. While her landings here on 23 April were unopposed, difficult surf and beach conditions challenged her skill. After several brief voyages to other New Guinea ports to transport reinforcements to the Hollandia area, "Centaurus" sailed for amphibious exercises in the Solomon Islands.