The estimates of the number of Japanese troops on Biak were out by a similar margin, resulting in heavy casualties. In the Battle of Biak, stubborn Japanese resistance halted the 41st Infantry Division, and forced its commander, Major General Horace H. Fuller, to appeal to Krueger for reinforcements. In response, Krueger sent the 163rd Regimental Combat Team from Wakde. MacArthur soon grew impatient, as he needed the airstrips on Biak to support Admiral Chester Nimitz's Invasion of Saipan. Nimitz's operation ultimately drew Japanese attention away from Biak.