The seventh round of the North American Free Trade Agreement (NAFTA) negotiations began in Mexico City with hopes of finalising more sections.

NAFTA country flags.

Mexico City:

Negotiators from Canada, the US and Mexico held a closed door meeting on Sunday at a hotel in the city's upscale Polanco neighbourhood, reports Xinhua news agency.

Mexico said the first day of talks will see 27 different working groups hold discussions on agriculture, good regulatory practices and rules of origin, among others.

Mexican Economy Minister and head negotiator Ildefonso Guajardo said this round will conclude on March 5 and could see up to seven sections or chapters finalised.

"It is a matter of making the necessary decisions, of which there are not too many, to close topics that have not been updated in 22 years," Guajardo said.

Also on the table are labour issues, pharmaceutical transparency, financial services and intellectual property rights.

Among the issues, the three NAFTA partners have been unable to agree on is rules of origin in the automotive sector, which stipulates what percentage of a vehicle should be regionally manufactured.

The US has proposed raising it to a minimum of 85 per cent within the NAFTA region, and at least 50 per cent from the US. However, Mexico and Canada want the rate to remain at 62.5 per cent.