South Korea is likely to get much more liberal access to New Zealand fishing waters under a free trade agreement (FTA) Prime Minister John Key will negotiate this weekend.

This is despite criticism of Korean-flagged ships in a ministerial inquiry into alleged labour and human rights abuses in waters here.

Key will be in Seoul over the weekend for a nuclear summit and will have a one-on-one meeting with Korean President Lee Myung-bak with a Korea-New Zealand FTA high on the agenda.

Diplomatic sources say Korea is demanding open access to New Zealand's exclusive economic zone in exchange for a free trade deal.

Key told reporters that the issue of human rights abuse allegations over Korean-flagged foreign charter vessels (FCVs) "may come up" in discussions.

But he made it clear he wants an FTA with Korea, New Zealand's fifth largest trading partner.

"The issue there is that we want to advance the FTA obviously," Key said.

A joint ministerial inquiry report last month said it was mainly Korean ships that were damaging New Zealand's international reputation and noted that most of the damaging incidents on FCVs involved Korean-flagged ships.

Key said the issues involved individual Korean companies and Foreign Affairs Minister Murray McCully had taken that up with the Korean Embassy in Wellington.

"Part of any FTA you have is that it still has to adhere to the laws that particular country.

"You cannot have Chinese labour laws operating here because a Chinese company wants to operate in New Zealand as part of an FTA. It will be the same for the Koreans."

Key stressed New Zealand exporters paid millions of dollars in South Korean tariffs and with an FTA "there are huge opportunities up there for us to do better."

He said the FTA would not be settled with his trip but would be significantly advanced now that Korea had settled deals with Europe and North America.

- © Fairfax NZ News