In an effort to isolate Australia, the Japanese planned a seaborne invasion of Port Moresby, in the Australian Territory of New Guinea. In May 1942, the US Navy engaged the Japanese in the Battle of the Coral Sea and halted the attack. The Battle of Midway in June effectively defeated the Japanese navy and the Japanese army launched a land assault on Moresby from the north. Between July and November 1942, Australian forces repulsed Japanese attempts on the city by way of the Kokoda Track, in the highlands of New Guinea. The Battle of Milne Bay in August 1942 was the first Allied defeat of Japanese land forces.