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.

Assigned to Transport Squadron 24, Mellena embarked 242 MPs and Army Engineers of the XIV Corps at Manila and sailed for Japan 7 September.

She battled typhoon seas off Honshū 18 September and arrived Okinawa a week later to embark units of the 1st Marine Division.

Mellena entered the Gulf of Zhili 3 October and during the next week she debarked the 1st Marines who were ordered to take control of the Tientsin area until Nationalist troops could be brought in to replace them.

Designated for conversion to a surveying ship (AGS) 26 January, she operated out of San Pedro under Service Force, Pacific Fleet, until 6 March when she was ordered to be disposed of rather than converted.