MEXICO CITY - Mexico, Canada and the United States have instructed their negotiating teams to continue talks on the North American Free Trade Agreement (NAFTA) next week, Mexico's Economy Ministry said on Friday.

Meanwhile, Mexican Economy Minister Ildefonso Guajardo, Canadian Foreign Affairs Minister Chrystia Freeland, and US Trade Representative Robert Lighthizer, are to meet again "as soon as possible" to evaluate any progress made, the ministry said.

On Friday, the three envoys wrapped up a meeting begun in Washington on Monday, in which "they worked intensely to identify points of agreement that would lead to the balance needed to reach a successful negotiation," according to the ministry.

The meeting concluded amid new criticism of the trade deal from US President Donald Trump, who described NAFTA as "a horrible disaster" for the American economy.

Trump was meeting in Washington with the representatives of ten US and foreign automakers to try to reach more flexible standards in fuel efficiency towards the year 2025.

This week, Paul Ryan, speaker of the US House of Representatives, said that for congress to approve a renewed NAFTA, an agreement in principle of the revamped trade deal had to be ready by May 17.

Guajardo said Mexico would not cede on key points in order to rush through an agreement.

"We have always said that we are not going to sacrifice quality and balance ... for time," Guajardo told reporters.

Talks this week focused on some of NAFTA's thorny issues, including rules of origin for the automobile industry, a US proposal to include a five-year sunset clause, and changes to the dispute resolution rules.