As the Tenaru battle was ending, more Japanese reinforcements were already on their way. Admiral Isoroku Yamamoto put together a very powerful expeditionary force. Their aim was to destroy any American fleet units in the area, and then eliminate Henderson Field. This force sortied from Truk on 23 August. Several other reinforcements, support, and bombardment groups sortied from both Truk and Rabaul. Three slow transport ships departed from Truk on 16 August, carrying the remaining 1,400 soldiers from Ichiki's (28th) Infantry Regiment plus 500 naval marines from the 5th Yokosuka Special Naval Landing Force. The transports were guarded by 13 warships commanded by Japanese Rear Admiral Raizō Tanaka, who planned to land the troops on Guadalcanal on 24 August. To cover the landings of these troops and provide support for the operation to retake Henderson Field from Allied forces, Yamamoto directed Chūichi Nagumo to sortie with a carrier force from Truk on 21 August and head towards the southern Solomon Islands. Nagumo's force included three carriers and 30 other warships. Yamamoto would send the light carrier "Ryūjō" on a possible bait role ahead of the rest of the fleet, and attack Guadalcanal to draw the attention of the American pilots. The aircraft from the two fleet carriers would then attack the Americans.