 The 3rd Marines served as the part of Defense Force, Samoan Group and underwent intensive jungle training.The regiment remained on American Samoa until May 1943, when it was ordered to New Zealand in order to reinforce newly activated 3rd Marine Division.The units of 3rd Marine Division moved to the staging area on Guadalcanal during August 1943 and began with the preparations for upcoming task – Bougainville in the North Solomon Islands.