The RNZN began to identify the need for a logistic support ship in the 1970s. Such a ship would be used to support the defence and foreign policies of the New Zealand government, particularly in the South Pacific region by providing sealift for the New Zealand Army's Ready Reaction Force (RRF), with secondary roles including disaster relief, civil defence, Antarctic supply, and United Nations operations. The 1978 Defence Review noted the need for such a vessel, with attention drawn back to the acquisition of such a ship in the 1987 Defence White Paper. A 1988 study indicated that the minimum requirement was a vessel able to transport 200 soldiers and equipment, and unload them either through beach landings or wharf facilities. The need for a transport vessel was again identified in the 1991 Defence White Paper, with such a vessel essential to meet the tasks specified for the New Zealand Defence Force in that document. A review subsequent to the 1991 White Paper proposed a less-capable vessel than previously, with the ship able to perform wharf landings only. As well as the transportation of soldiers, the ship was envisaged for use during civil emergencies in South Pacific nations to deliver supplies of extract New Zealand citizens, and to keep transport routes to New Zealand's offshore islands, or across Cook Strait, if civilian services became restricted or unavailable. The review concluded that the acquisition of a mid-size roll-on/roll-off vessel for use as a military sealift ship should be prioritised; a Mercandian 1500-type vessel, capable of transporting 50% of the RRF's vehicles and equipment, was seen as the minimum standard, although a larger vessel like "Union Rotorua", almost able to deploy the entire RRF, was preferred.