The Japanese continued to experience problems in delivering sufficient supplies to sustain their troops on Guadalcanal. Attempts to use only submarines the last two weeks in November failed to provide sufficient food for Hyakutake's forces. A separate attempt to establish bases in the central Solomons to facilitate barge convoys to Guadalcanal also failed because of destructive Allied air attacks. On 26 November, the 17th Army notified Imamura that it faced a food crisis. Some front-line units had not been resupplied for six days and even the rear-area troops were on one-third rations. The situation forced the Japanese to return to using destroyers to deliver the necessary supplies.