Following outfitting, shakedown, and post-shakedown repairs, "Belfast" stood out of San Pedro, California, on 30 April 1944 and headed for Australia. After stopping at Nouméa, New Caledonia, "Belfast" reached Cairns, Australia, at the end of May 1944. From there, she moved into the Southwest Pacific theater of operations to serve as a patrol vessel and convoy escort. During the summer and early autumn of 1944, she supported the latter stages of the leapfrog assaults along the northern coast of New Guinea. She took part in the Noemfoor landing on 2 July 1944 and in the assault on Cape Opmarai four weeks later.