In late February 1942, as a Japanese invasion of Nauru and Ocean Island was feared, the Free French destroyer Le Triomphant departed the New Hebrides to evacuate both places.

On 11 May 1942, the Imperial Japanese invasion force departed Rabaul, under the command of Rear Admiral Shima Kiyohide and consisting of the cruiser Tatsuta, the minelayers Okinoshima (flagship) and Tsugaru and the destroyers Uzuki and Yūzuki, covered by the 5th Cruiser Division, under the command of Vice Admiral Takeo Takagi, consisting of the heavy cruisers Myōkō and Haguro with the Destroyer Division 30 destroyers Ariake, Mochizuki, Shigure and Shiratsuyu.

[1] While steaming through driving rain off New Ireland and west of Buka Island, Okinoshima, which had been damaged by airplanes from Yorktown during the invasion of Tulagi on 4 May 1942, was torpedoed at 04:52 by the United States Navy submarine S-42 (Commander Oliver G. Kirk) and severely damaged.

Rear Admiral Shima transferred his flag to Yūzuki southwest of Buka Island, Bougainville.

A second invasion force departed Truk on 26 August 1942, consisting of the cruiser Yūbari, the destroyers Oite, Yūzuki, Ariake, Yūgure and Yūnagi, and the transport Hakozaki Maru.

During the Japanese occupation of Nauru, American aircraft repeatedly bombed the island's facilities.