A joint Australian-American effort against Borneo kept "Waller" busy from May to July. "Waller" participated in this campaign by escorting convoys to Tarakan Island, Brunei Bay, and Balikpapan, as well as by covering minesweeping operations in the Miri-Lulong area, below Brunei Bay. She then rejoined the 3d Fleet early in August to be in readiness for the projected invasion of the Japanese home islands. But while en route toward Honshū, escorting a convoy, "Waller" received the most welcome news that the Japanese had accepted the unconditional surrender terms of the Potsdam Declaration.