The federal New Democrats want the prime minister to appear before an emergency meeting of the international trade committee to disclose the Liberals' priorities for NAFTA negotiations.

International Trade critic Tracey Ramsey says they were pleasantly surprised to hear Wednesday that Justin Trudeau would be happy to sit down with opposition parties to discuss the issue.

Trudeau made the remarks after both the Conservatives and NDP forced a summer meeting of the Commons' committee Friday to try and suss out the Liberals' approach to NAFTA talks.

They begin on Aug. 16 and in accordance with U.S. law, the Trump administration laid out its own goals this week including what it sees as market access issues with Canadian products such as dairy, wine and grain.

Canadian lawmakers are not obligated to lay out negotiating goals for the deal, and that's what opposition MPs are trying to rectify via Friday's committee meeting.

Originally they were seeking to hear from Foreign Affairs Minister Chrystia Freeland, Finance Minister Bill Morneau and International Trade Minister Francois-Philippe Champagne.

A spokesman for Freeland said she has happily accepted the invite.

"We are working with the committee to confirm a date as quickly as possible," Adam Austen said in an email.

But the NDP also want Trudeau on the witness list.

The Liberals said NAFTA talks would amount to a tweak and that's not the case, Ramsey said.

"We were pleasantly surprised to hear Prime Minister Justin Trudeau suddenly claim yesterday that he would be happy to sit down with opposition parties and discuss the priorities for the negotiations," she said in a statement.

"We take (Prime Minister) Trudeau's statement as genuine, and based on that we are confident that he will have no problem agreeing to this simple request."