Tsukamoto did not continue to press the advance but waited for Horii to concentrate his main force, estimating that the Australian force holding Kokoda had numbered around 1,000, to 1,200. The force available to Horii was based on five infantry battalions with supporting arms and services variously reported at 3,000 and 5,000 strong. Horii planned to attack with four infantry battalions, holding one of these in immediate reserve to exploit the result. The force that engaged the Australians at Isurava totaled 2,130, including artillery.