"Heermann" was then assigned to the Third Fleet and Task Force 39 on 18 March 1944 after stopping at Majuro Lagoon and then Port Purvis on Florida Island, in the Solomons. For the next month the destroyer escorted convoys which were occupying Emirau Island and seeking out enemy supply barges along the coast of New Hanover. Following a stop at Purvis on 3 June, "Heermann" took part in the bombardment of a tank farm on Fangelawa Bay, New Ireland on 11 June, and then performed ASW patrols from the Solomons towards the Admiralty, Caroline, and Marshall islands until 26 June. In mid-1944, "Heermann" escorted merchant shipping from Espiritu Santo, New Hebrides and Nouméa, New Caledonia. The destroyer returned to Port Purvis and departed on 6 September 1944 with Rear Admiral William Sample's escort carrier force, providing escort during the invasion of the Palau Islands. Following this, the destroyer was detached for operations in the Philippine Islands.