Edwini Kessie's comment comes after Papua New Guinea and Fiji poured cold water on the current form of PACER Plus.
Pacific Islands Forum leaders last September said they wanted PACER Plus negotiations, which began in 2009, to be concluded by mid-2016.
PNG's Trade Minister, Richard Maru says he sees little benefit for PNG in the agreement.
He says that in its current form, especially the push to remove tariffs and duties, PACER Plus will reduce employment opportunities and kill his country's manufacturing sector.
Mr Maru says that any trade agreement PNG enters into as a country must be to grow the private sector, manufacturing sectors and employment opportunities.
But Dr Kessie says Pacific countries would retain the right to regulate, and also to protect infant industries.
"The concern of Papua New Guinea and Fiji, basically, they want to have what is called an infant industry clause, which we are working on at the moment in the negotiations. And I'm optimistic that we will be able to find a solution on this issue."