Following the Guadalcanal Campaign, Fields was appointed commanding officer of the 1st Battalion, 11th Marines. His new command was already in Melbourne, Australia for rest and refit after heavy casualties. While in Australia, Fields was promoted to the rank of lieutenant colonel in May 1943. The 11th Marines were sent to Cape Sudest at New Guinea in September 1943 in order to prepare for upcoming Battle of Cape Gloucester at New Britain. The Gloucester operation was launched at the end of December 1943, and Fields went ashore with his battalion. He subsequently coordinated the support artillery fire during the attack on Aogiri Ridge and later during Natamo Point operation in late January 1944, while provided artillery support for the 5th Marines, which was trying to cut off Japanese withdrawal routes. Fields was decorated with the Bronze Star Medal with Combat "V" for his service at Gloucester.