As nations gather in Auckland to sign giant trade deal, NZ eyes role as secretariat to steer in more members.

As critics of the Trans-Pacific Partnership gather in Auckland for a major show of force tomorrow, TPP Trade Ministers will be focused on its expansion beyond the 12 members, before the ink is dry on the deal.

They will also hear the opening stages of a bid by New Zealand to make Auckland the permanent secretariat of the giant trade deal, something Prime Minister John Key may gently promote when he hosts the dignitaries to dinner tonight.

Trade Minister Todd McClay will chair the ministerial meeting before ministers from 12 countries sign the contentious trade agreement.

Mr McClay told the Herald more work needed to be done on what a secretariat would look like and no decision would be made quickly.


But the Auckland Council and Auckland business community supported it. "I think we would make a very strong bid for it."

A secretariat, however, would have to be independent of the host Government.

Other countries thought to be interested in hosting a secretariat include Singapore, where former Reserve Bank Governor Alan Bollard heads up the Apec secretariat.

Chief Trans-Pacific Partnership negotiators, led by New Zealand's David Walker, will be meeting in Auckland this morning.

Top of their agenda will be what happens to prospective new members over the next two years, before the deal is able to come into force.

Indonesia, South Korea, Thailand and Columbia are among those countries that have expressed some interest in joining.

"There will be countries that are very keen," Mr McClay said. "In some cases we will want them to do various things to get ready and in other cases we will need to give them a pretty clear steer.

"It's 40 per cent of the world's GDP at $27 trillion worth of TPP spend.

"There are a lot of countries who are thinking it would be madness not to be involved."

Mr McClay said if a small secretariat were established, it could do more work for ministers on the issue of accession to the TPP.

In his view, countries would have to be willing to sign up to what was already agreed. There would be no reopening of talks, except on tariffs.

United States Trade Representative (minister) Mike Froman, who chaired the TPP talks, is expected to report to other ministers on the prospects of the deal being passed by the Congress before the summer break in July.

A suggestion by visiting US TPP critic Lori Wallach that the US would try to reopen talks on the patent period for biologic drugs was dismissed in terms of New Zealand.

Mr Key said last night that there would be no change to the five years New Zealand negotiated.