Reassigned later in the month, the attack transport took on
Marines and headed for the
Pacific. On 9 October she arrived at
Wellington, New Zealand, departing, on the 27th, for
Efate, the staging area for the
Tarawa assault. By 20 November she stood off that atoll as flagship of TransDiv 18. Afterward, with casualties, elements of the remaining units of the
2nd Marine Division, and several POWs, she returned to
Hawaii. During December and January 1944, she conducted training exercises in the Hawaiian area with Marine and Army personnel. On 22 January she sailed for her third amphibious operation,
Kwajalein, participating in the assault there on the 31st, and returning casualties and POWs to
Pearl Harbor in February. She then sailed on to
San Diego, arriving 17 February for availability and 2 months of training off southern
California. Underway for the combat area again in June, she participated in the assault on
Saipan, again landing personnel of the
2nd Marine Division, in spite of reefs,
mortar fire, and aerial resistance. After the
Battle of the Philippine Sea, she once more transported casualties and POWs to Hawaii, whence she sailed, 9 July, for
Guam with units of the
77th Infantry Division. Arriving on the 22nd, she remained in the assault area for 7 days before returning, with casualties, to Pearl Harbor for a brief availability. In September, with
96th Infantry Division troops embarked, the transport sailed west again, arriving at
Manus, the staging area for the upcoming
Philippine offensive, 3 October. By dawn, 20 October, she was off
Leyte. Unloaded by 1800, on the 21st, she got underway in time to clear the gulf before the arrival of
Japanese naval units en route from the
Sulu Sea. Heading southeast, she steamed to
New Guinea, whence she lifted elements of the
11th Airborne Division to Leyte. She then sailed to
New Britain, took on units of the
40th Infantry Division and returned to Manus to stage for the assault on
Luzon. Departing 31 December, she encountered aerial resistance in
Lingayen Gulf, 1945-01-09, and, on the 10th, endured a Japanese suicide swimmer attack before departing for Leyte to take on
1st Cavalry Division troops for transport to the
Luzon beaches.
Monrovia then returned to the
Solomons, took on units of the
6th Marine Division, and, as flagship, TransDiv 36, conducted amphibious exercises in preparation for
Operation Iceberg, the
invasion of Okinawa. From the Solomons, she proceeded to
Ulithi to join other ships assigned to TF 53, the northern attack force, and headed for the
Hagushi beaches. By dusk on 1 April, she had landed all her marines, but, because of nightly retirements, did not complete discharging her cargo until the 5th. She then steamed eastward, arriving at
Portland, Oregon, on the 28th for overhaul.
Monrovia returned to the western Pacific after the Japanese surrender and immediately commenced transporting occupation troops and supplies to
China and
Japan, returning to the United States with battle weary veterans. She continued to transit the Pacific, between the west coast and Japan, as a cargo and personnel carrier until the spring of 1946, when she was ordered to the east coast for inactivation. On 1946-07-31, she reported to the
Atlantic Reserve Fleet, at Norfolk, decommissioning there 1947-02-26. ==Cold War Service==