In April 1942, the army and navy developed a plan that was titled Operation Mo. The plan called for Port Moresby to be invaded from the sea and secured by 10 May. The plan also included the seizure of Tulagi on 2–3 May, where the navy would establish a seaplane base for potential air operations against Allied territories and forces in the South Pacific and to provide a base for reconnaissance aircraft. Upon the completion of "Mo", the navy planned to initiate Operation RY, using ships released from "Mo", to seize Nauru and Ocean Island for their phosphate deposits on 15 May. Further operations against Fiji, Samoa and New Caledonia (Operation FS) were to be planned once "Mo" and "RY" were completed. Because of a damaging air attack by Allied land- and carrier-based aircraft on Japanese naval forces invading the Lae-Salamaua area in New Guinea in March, Inoue requested Japan's Combined Fleet send carriers to provide air cover for "Mo". Inoue was especially worried about Allied bombers stationed at air bases in Townsville and Cooktown, Australia, beyond the range of his own bombers, based at Rabaul and Lae.