Japanese forces launched air strikes on key areas and gained air superiority. Following the airstrikes, landings were made at several locations targeting airfields and other important points in the area. In addition to the landings at Miri, the Japanese forces made landings at Seria, Kuching, Jesselton and Sandakan between 15 December 1941 and 19 January 1942. After these main objectives in Borneo were completed, the Japanese forces planned a three-pronged assault southward using three forces named Eastern Force, Center Force and Western Force. The aim of this assault was to capture the oil resources in the East Indies. The Eastern Force was to advance from Jolo and Davao and move on to capture Celebes, Amboina and Timor, while protecting the Center Force's flank. The Center Force was to capture oil fields and airfields in Tarakan Island and Balikpapan. Both these forces would support the Western Force, which was to attack and capture the oil refineries and airfields in Palembang. The Japanese forces launched the assault on 11 January and landed at Tarakan. To coordinate the fight against the Japanese, the American, British, Dutch, and Australian forces combined all available land and sea forces under the American-British-Dutch-Australian Command (ABDACOM or ABDA) banner. This command was activated on 15 January 1942, with the overall commander being British Field Marshal Sir Archibald Wavell. The command structure had the American Army Air Force Lieutenant General George Brett as deputy commander, the British Lieutenant General Henry Royds Pownall as chief of staff; under them were the American Admiral Thomas C. Hart as naval commander, the Dutch Lieutenant General Hein ter Poorten as ground forces commander, and the British Air Chief Marshal Sir Richard Peirse as the air commander. Although the forces were combined, they had differing priorities: the British believed the defense of the territory of Singapore and the eastern entrances to the Indian Ocean (the route to British Ceylon and British India) to be paramount, the Americans and Australians did not want a total penetration of Southeast Asia that would deprive them of bases necessary for any serious counterattack, and the Dutch considered Java and Sumatra, their "second homeland where [they] had been trading and living for over three centuries", to be the most important place to defend. Even the combined forces could not stop or even slow the Japanese advance due to their much greater numbers; to face the Japanese attacking naval forces,