United States lobby groups are warning that imports of New Zealand wine and dairy foods could be at risk if New Zealand commits to plain packaging of tobacco products.
The Government has agreed in principle to the move, with public consultation due to begin later this year.
The statement has been issued by six organisations, including the US Chamber of Commerce, the TransAtlantic Business Dialogue, the National Association of Manufacturers, the United States Council for International Business and the National Foreign Trade Council.
The statement says the New Zealand Government is considering the destruction of legitimate trademark protection and branding, which are protected by laws and international treaties.
It also says the move is troubling, coinciding as it does with talks aimed at boosting free trade between the two countries.
It warns New Zealand to consider the consequences for exports such as dairy and wine.
Auckland University Professor Jane Kelsey says the US groups involved are behind the push for the Trans Pacific Partnership, through which they hope to secure the right to sue governments which tamper with intellectual property rights.
She says the tobacco companies who belong to some of these groups are already suing the Australian government over the issue.
However Stephen Jacobi from the New Zealand United States Council says it's unlikely the plain packaging move will affect free trade negotiations and any threat to exports is a bit far fetched.
He says there is a provision in the agreement, and in existing trade deals, that allows the government to protect public health.
The Labour Party says New Zealand would be on firm footing with its trade obligations if it enforced plain packaging.
The party's associate health spokesperson, Iain Lees-Galloway, says New Zealand has reserved the right to set its own public health policy with respect to any trade arrangement.