"Welles" and her traveling companions arrived at Funafuti in the Ellice Islands on 21 January and remained there for a week before getting underway for New Guinea. The destroyer arrived at Milne Bay on 5 February and joined the U.S. 7th Fleet. Later in the month, she escorted a convoy of LSTs to Cape Gloucester on the island of New Britain. On 29 February, "Welles" provided gunfire support for elements of the Army's 1st Cavalry Division then landing on Los Negros Island in the Admiralties. During that operation, the destroyer came under fire from enemy automatic weapons and at least one field gun but sustained no damage. After completing her portion of the mission, she moved out to the transport area to provide antisubmarine defense. Periodically, she returned close to shore to provide all fire for American troops fighting ashore.