New Zealand's Trade Minister thinks it will still be some time before the details of the Trans-Pacific Partnership are clear.

Representatives of the 11 countries still involved met in Vietnam over the weekend, and committed to bringing the deal into force in its current form.

Trade Minister Todd McClay told Mike Hosking working out the ramifications of the US no longer being in the deal, will take time.

"We're going to have to work through it in officials level some of the detail - how do you take an agreement of 12 and actually turn it into 11, but the countries are saying there shouldn't be renegotiation, that's very important to us."

Prime Minister Bill English is more optimistic than ever that the agreement will get over the line.

Mr English told Mike Hosking over the past few months New Zealand has done a lot of background work on the TPP.

"We're probably more optimistic that we have been for a while that this could move through with benefits for New Zealand and for the region."

LISTEN ABOVE AS TRADE MINISTER TODD MCCLAY SPEAKS WITH MIKE HOSKING