The Japanese Port Moresby Invasion Force, commanded by Rear Admiral Kōsō Abe, included 11 transport ships carrying about 5,000 soldiers from the IJA's South Seas Detachment plus approximately 500 troops from the 3rd Kure Special Naval Landing Force (SNLF). Escorting the transports was the Port Moresby Attack Force with one light cruiser and six destroyers under the command of Rear Admiral Sadamichi Kajioka. Abe's ships departed Rabaul for the trip to Port Moresby on 4 May and were joined by Kajioka's force the next day. The ships, proceeding at , planned to transit the Jomard Channel in the Louisiades to pass around the southern tip of New Guinea to arrive at Port Moresby by 10 May. The Allied garrison at Port Moresby numbered around 5,333 men, but only half of these were infantry and all were badly equipped and undertrained.