Jesus Seade, Mexico's undersecretary for North America, pictured November 27, has said a USMCA deal could be agreed soon. (Photo: AFP)

Mexico's trade negotiator said Friday he was cautiously optimistic about finalizing a new North American trade pact as soon as next week, after meeting with Canadian Prime Minster Justin Trudeau in Ottawa.

Negotiators from the United States, Mexico and Canada signed a deal last year on a new treaty to replace the 1994 North American Free Trade Agreement (NAFTA), but only Mexico ratified the accord.

"If the amendments are acceptable, are improvements, there's no reason why we should not be shaking hands next week" on the rebranded US-Mexico-Canada Agreement (USMCA), Undersecretary for North America Jesus Seade told reporters.

His meeting with Trudeau and Deputy Prime Minister Chrystia Freeland focused on changes to the accord as well as side deals requested by the United States.

Democrats in Washington and US labor representatives had previously raised concerns about the treaty, looking for stronger guarantees that new Mexican labor laws will be enforced, among other issues.

"With a lot of discipline, legislators in each country (could ratify the accord) by the end of the year," Seade said.

But "if there's something complicated that needs to be discussed and we have to again go back to (US) Democratic legislators and all that, then it could take more time and (go) into next year."

Trudeau said at the start of their meeting Friday that "we know there's still a little more work to do."

Seade said Pelosi's request for reworking the agreement in the areas of labor, environment, dispute settlement and pharmaceuticals were "valid views."

A red line for Mexico, however, might be on enforcement: "We would not accept Lone Ranger inspectors... in (Mexican) factories," he said.

Ottawa has said it would ratify the agreement in lockstep with Washington.