The Japanese plan to extend their Pacific control was to set up a base at Tulagi in the Solomons for long-range amphibious aircraft. At the same time they would take Port Moresby.Control of the port and airfield at Port Moresby would mean that Japanese-held islands would be safe from land-based air attacks, and the Japanese Air Force would be free to attack Queensland ports and airfields at Horn Island, Cooktown, Coen and Townsville.