The battle formed part of the wider Pacific War and involved New Zealand and US forces fighting against Japanese troops.

The attack on the Treasury Islands would serve the long term Allied strategy of isolating Bougainville and Rabaul and the elimination of the Japanese garrison in the area.

Mono Island, with its high features, offered the prospect of serving as a radar station to provide early warning for aerial and naval surface attacks during the Cape Torokina operation.

[6] The Allies also hoped that the landing would convince the Japanese that their next move would be on the Shortlands or at Buin on the southern tip of Bougainville, instead of the Cape Torokina – Empress Augusta Bay area.

[14] Following this, two infantry battalions—the 29th and 36th—landed around Falamai on the southern coast of Mono Island, approximately 2 miles (3.2 km) away from Blanche Harbour's western entrance.

In the ensuing melee, 12 Japanese aircraft were shot down by supporting AirSols fighters and naval gunfire, while Cony was hit aft twice, resulting in the death of eight of her crew and the wounding of 10 others.

Resistance to the initial landing was light and was quickly overcome with only a small number of casualties, which came exclusively in the first wave of the assault.

Mopping up operations began, and over the course of 11 days several minor engagements took place as patrols sought to flush out Japanese troops that were hiding out mainly in caves on the northern coast.

[22] The operation, in conjunction with a raid on Choiseul, served to divert the attention of the Japanese Seventeenth Army from the next major Allied target in the Solomon Islands campaign.

Four 6-by-18-foot (1.8 by 5.5 m) pontoon barges were secured to 16-by-16-foot (4.9 by 4.9 m) timber crib piers, which were connected to the shore by ramps made of girders covered with wooden planks.

[24] PT boats based in the Treasury Islands helped protect Allied forces landing at Torokina, while a radar site was established around Soanotalu, which played an important part in the success of that operation.

[25] The airbase was used by the medium bombers of the USAAF's 42d Bombardment Group and the U.S. Marine Corps' VMB-413, while the base facilities were utilised by the U.S. Navy's Acorn 12.