A lobby group pushing for greater trade with the United States says research shows trade liberalisation in the Asia-Pacific region would boost the New Zealand economy.
The New Zealand United States Council says the Trans Pacific Partnership (TPP) could add about $2.1 billion a year to the economy by 2025.
The council says the research shows it would boost New Zealand's GDP by 0.83%.
The research was carried out by Hawaii-based think tank East-West Center and reviewed for the council by the New Zealand Institute of Economic Research (NZIER).
The Trans Pacific Partnership is under negotiation and if approved would free up trade between New Zealand, the US and several other countries, but has come in for criticism from union and left-wing opponents.