The Invasion of Buna–Gona, called Operation RI by the Japanese, was a military operation by Imperial Japanese forces to occupy the Buna–Gona area in the Territory of Papua during the Pacific campaign of the Second World War. The initial landings and advance on Kokoda occurred between 21 and 27 July 1942. The Japanese invaded and occupied the location in preparation for an overland attack on Port Moresby along the Kokoda Track. The landing marked the start of the Kokoda Track campaign. The landings were not directly opposed by land forces but were engaged by elements of Maroubra Force as they advanced on Kokoda. This initially included B Company of the 39th Battalion, patrols of the Papuan Infantry Battalion (PIB) operating in the area and a small number of the Australian New Guinea Adminis