US and Mexican trade negotiators are making progress in their discussions on the revamping of the North American Free Trade Agreement (NAFTA), according to Mexican Economy Minister Ildefonso Guajardo.

However, he cautioned that while negotiations are "well-advanced", the two sides are "not there yet."

Guajardo and Mexico's Foreign Minister Luis Videgaray have been involved in discussions with Washington officials for well over a month, looking to iron out issues in the 24-year-old NAFTA deal. US President Donald Trump has long-since vowed to tear up the agreement, describing it as "the worst trade deal maybe ever signed anywhere, but certainly ever signed in this country."

Read more: US trade official hopes for breakthrough in NAFTA talks

Among the bilateral issues that Mexican officials and the US delegation, led by trade representative Robert Lighthizer, have been discussing are contentious topics such as rules for the auto market, a major area of strategic economic concern for Mexico.

Standing on guard for Canada

A breakthrough in the talks was expected this week but Guajardo said that discussions would continue into the weekend and into next week.

He said that it was essential that Canada re-engaged with the talks. Canada's top diplomat and chief NAFTA negotiator Chrystia Freeland said earlier this week that Canada would rejoin the discussions once the bilateral issues between Mexico and the US had been resolved.

Read more: Mexico pushes ahead with speedy NAFTA game plan

However, one major stumbling block involving all three countries is the US demand for a so-called "sunset clause", which would oblige the three countries to renew the trade pact every five years.

"There's been no indication of flexibility from the US on this issue," a senior Canadian official told the AFP news agency on Thursday.

"Highly complex"

Since talks between Mexico and the US resumed last month, the main focus has been on Trump's grievance that the NAFTA agreement has undercut American manufacturing to Mexico's benefit.

Unresolved sticking points, such as rules of origin for cars, continue to present roadblocks in the talks, which are due to resume in Washington on Friday morning.

Both US and Mexican officials are pushing for an agreement which will bring Canada back to the table as soon as possible. "We need to get an engagement with Canada and the only way that can happen is if we continue through the weekend and into next week," said Guajardo.

Nonetheless, he said the negotiations remained "highly complex."

aos/hg (AFP, Reuters)