In March, she was assigned to convoy escort duties in and around Malaysia and the Dutch East Indies until she was transferred to Rabaul in early 1943 to ferry troops around New Guinea and the Solomon Islands.

[4] Nagatsuki was one of six Mutsuki-class ships reconstructed in 1935–36, with their hulls strengthened, raked caps fitted to the funnels and shields to the torpedo mounts.

[3] In the late 1930s, the ship participated in combat during the Second Sino-Japanese War, covering the landings of Japanese troops in central and southern China, and the Invasion of French Indochina.

While at Lingayen Gulf, Nagatsuki suffered light damage due to strafing attacks by USAAF aircraft, which left one crewman dead and five injured.

[5] In early 1942, Nagatsuki was assigned to escorting troop convoys from French Indochina for Operation J (the invasion of Java, Netherlands East Indies), From 10 March 1942 Nagatsuki and Destroyer Division 5 were reassigned to the Southwest Area Fleet and escorted troop convoy from Singapore to Penang, and Rangoon.

The destroyer returned to Sasebo Naval Arsenal for repairs on 19 September, and rejoined the fleet on 9 November, continuing escort patrol duties.

The ship participated in several Tokyo Express troop transport missions throughout the Solomon Islands through the end of June, especially to Kolombangara and Tuluvu.

The crew suffered eight dead and thirteen injured, but the survivors later reached the Imperial Japanese Army base at Vila on Kolombangara on foot.