The president of General Motors' Mexican unit reportedly has advised suppliers to prepare to resume operations after the Mexican government said the automotive industry could exit the coronavirus lockdown before 1 June with adequate safety measures.

"We are now beginning a new phase given the Mexican government's official announcement earlier this week to consider the transportation manufacturing industry as essential for the country's economy," Francisco Garza, president of General Motors de Mexico, wrote in an email to suppliers dated on Friday that was viewed by the Reuters news agency.

Noting the Mexican government was due to publish final safety rules today Monday, 18 May, Garza added: "Once those final guidelines are known, we will be in a position to move swiftly to comply."

GM was tentatively planning to restart operations at its vehicle assembly plant in Silao on Wednesday, according to a message to workers seen by Reuters on Sunday.

Workers at the plant in the central state of Guanajuato that had been idled for weeks due to the coronavirus outbreak had previously been told to plan to return to work on Monday, the news agency noted.

A GM spokeswoman told Reuters the company could not confirm when it would restart operations at any of its facilities in Mexico because it was awaiting more guidance from the government.

The government's announcement, made on Friday, means that automakers from as early as this week can begin reconnecting supply chains between Mexico and the rest of North America, which depends heavily on parts made south of the US border, Reuters said.

Senior US politicians and auto companies had pressed the Mexican government to reopen factories.

Reuters noted some politicians were wary, however, of opening too fast. Mexico registered its first case of the coronavirus weeks after the United States and Canada and the toll of daily infections and deaths in the country reached new peaks over the past few days.