The United States says it wants a trade deal involving New Zealand to contain provisions that would make it harder to sue governments for introducing anti-smoking measures.
Public health groups are welcoming the idea but say pending more detail, it is hard to judge how effective it would be in protecting measures such as plain packaging.
The Trans-Pacific Partnership had been seen as a threat to plans to introduce plain cigarette packaging in New Zealand, especially if it gave American tobacco companies the right to sue the Government.
However, the US Trade Representative's Office says the nine- country deal should protect governmental authority to enact measures that reduce tobacco use.
Anti-smoking group ASH is welcoming the statement, but wants more information.
It says because the negotiations for the Trans-Pacific Partnership are behind closed doors, it is difficult to know the exact US position and whether it deserves New Zealand's support.
ASH director Ben Youdan says New Zealand should not sign anything that would make it harder to legislate anti-smoking measures in the future.