She rejoined the BPF at Sydney (now attached to the United States 3rd Fleet) and on 31 July escorted the battleship to Guam, together with "Wager", where they arrived on 9 August. Admiral Bruce Fraser, Commander-in-chief of the BPF, conferred with U.S. Admiral Chester Nimitz, the Commander-in-Chief Pacific Fleet Headquarters. The ships then proceeded to rendezvous with the main body of the fleet off the coast of Japan on the 16th. "Whelp" was the first Allied ship to enter Sagami Bay on 27 August, leading the way for "Duke of York" and the American battleships and . She was present at Tokyo for the formal surrender of the Japanese on 2 September. She left Tokyo on 9 September and, following an overnight stop at Okinawa on 11/12 September, arrived at Hong Kong with Admiral Fraser aboard. He accepted the surrender of the Japanese forces in Hong Kong on 16 September.