Australia and their northern neighbor Papua New Guinea (the eastern half of New Guinea Island) are jointly reviving an old American World War II naval base on Manus Island, which is off the northeast coast of Papua New Guinea. The U.S. Navy first built the base in 1944 as Lombrum Naval Base, which served as a major advance base for American naval forces as well as marines and soldiers, who stayed at nearby camps before moving on to a combat operation. Lombrum was capable of performing major repairs on most warships and also resupplied ships before they moved on to a combat zone. Lombrum was shut down in 1946 as the American forces demobilized and redeployed after the war. Australia took over Lomdrum in 1950 and used it until 1974 as a replacement for their Dreger Harbor base on the east coast of New Guinea. In 1974 newly independent PNG (Papua New Guinea) armed forces inherited the Manus facility. The base had declined in activity since 1950 and PNG used it as a patrol boat base. In 2018 Australia and PNG, alarmed at aggressive Chinese activities in the area, agreed to jointly upgrade and operate what was now again called the Lombrum naval base. The expansion deepened the harbor by two meters (six feet) so that larger ships could use it and added facilities (electrical, water, sewage) for more personnel and rebuilt and extended some of the piers. Radars and other sensors are being installed, the better to monitor naval activity. The upgraded base can handle more PNG patrol boats as well as frigates and destroyers from Australian, the U.S. Navy and other friendly nations sending warships to the area, especially when involved with deterring China.
Most of the expansion work was done by PNG personnel and PNG citizens comprise most of the base personnel. Manus itself is the largest of the Admiralty Islands, which are part of the Bismarck Archipelago. Manus was occupied by the Japanese from 1942 until an American offensive cleared them out in 1944. Manus was always seen as a key island in the Bismarck Archipelago and holding Manus gave you control of access to the South Pacific and PNG/Australia/New Zealand and many smaller islands.