What is now Papua New Guinea consisted of two territories under Australian administration, the Territories of Papua and New Guinea. Upon the outbreak of the Second World War, the New Guinea Volunteer Rifles were organized as a militia unit of white expatriates in the New Guinea territory, while the bulk of the Australian military was deployed in the Mediterranean. Japanese forces invaded beginning in January 1942 with the Battle of Rabaul; in the following months Japan occupied most of the Territory of New Guinea. From late 1942 until the Japanese surrender, the Allies, mostly Australian and US forces, cleared the Japanese first from Papua, then the Territory of New Guinea, and finally from Dutch West New Guinea. The campaign resulted in heavy losses for Japan. Disease and starvation claimed more Japanese lives than combat. Allied forces effectively besieged enemy garrisons, cutting them off from food and medical supplies.