Mexico City, Mar 6 (IANS): The seventh round of the North American Free Trade Agreement (NAFTA) talks ended hereon a mixed note with the US calling the progress not good enough but Mexico remaining upbeat.

On Monday night, US Trade Representative Robert Lighthizer said only six of NAFTA's 30 chapters have been closed so far, reports Xinhua news agency.

"We have not made the progress many had hoped... Our time is running very short. I fear that the longer we proceed, the more political headwinds we will feel."

Lighthizer said that the upcoming Mexican presidential elections, US mid-term elections, and polls in Canada's Ontario and Quebec povinces were complicating matters.

However, Mexican Economy Minister Ildefonso Guajardo said the seventh round of talks had created "an adequate landing strip" for a successful resolution.

Differences in unresolved chapters such as e-commerce, telecommunications, energy and technical obstacles to trade were only "minimal", he said. "As we move forward, we will begin to fulfill our objectives and close our differences."

Countering Lighthizer's call for haste, Guajardo said Mexico will take the time it takes, at least until the mandate of President Enrique Pena Nieto ends on November 30.

Canadian Foreign Minister Chrystia Freeland said there is still hard work ahead for a successful updating of NAFTA.

Before the eighth round of talks starts in April, negotiators will meet to resolve the thorniest issues, such as the clause to terminate the NAFTA and the rules of origin in the automobile sector.

Canada, the US and Mexico have been carrying out intense negotiations to redraft NAFTA since August 2017 after American President Donald Trump said the deal has been unfair to Washington.