The Papuan Infantry Battalion (PIB) along with the 1st and 2nd New Guinea Infantry Battalions were amalgamated to form the Pacific Islands Regiment in November 1944. The 3rd and 4th New Guinea Infantry Battalions joined the regiment upon their formation in 1945, although 4 NGIB was soon disbanded, and the 5th New Guinea Infantry Battalion—although authorised—was never raised. Established at Camp Diddy, near Nadzab, and drawing personnel from the PIR's depot battalion, 3 NGIB completed training there until August 1945. Formed late in the war the battalion took no part in the Allied campaigns in New Guinea, although a few of its members saw service with 2 NGIB during the Aitape–Wewak campaign, suffering a number of casualties. On the final day of the war, 3 NGIB was declared operationally ready and began moving to New Britain, where it undertook garrison duties around Rabaul in the immediate post war period.