Tesla interviewed engineers Friday in Monterrey, Mexico, to prepare for increased production at its Fremont, Calif. assembly plant.

The company held interviews at a hotel job fair in one of Mexico’s industrial centers, and scheduled other meetings over the weekend.

The region offers a pool of experienced manufacturing engineers who’ve worked for General Motors, Ford, Fiat Chrysler, Volkswagen, and other global automakers. Reuters reported there are currently 19 automotive plants operating in Mexico.

Tesla needs to bring in talented engineers as Model 3 production and launch approach, and the company prepares to grow production six-fold over last year with a 500,000 vehicle per year target. The electric carmaker faces a steep challenge finding engineers skilled in working with robotics and other automation at its at its assembly plant with talent in short supply.

Tesla’s endeavor comes at a time when the Trump administration has placed automakers, and other industrial sectors such as the trucking industry, in a tight spot with a controversial review of immigration policies and a plan to bail out of the North American Free Trade Agreement (NAFTA).

The Trump administration is reviewing immigration rules for bringing highly skilled foreign workers to the U.S., which has become an integral part of the domestic workforce in recent years. Federal agencies have faced heavy scrutiny since detaining immigrants earlier this year under the new administration.

President Trump has also rattled auto executives with plans to pull out of NAFTA with Mexico and Canada. Trump has made comments about hitting automakers with a 35 percent tariff to manufacture cars in Mexico and ship them north for sale in the U.S.

Meanwhile on a less controversial front, Tesla had a bit of a mix-up during its weekend recruitment event in Northern Mexico. Dozens of prospects were turned away, thinking it was an open job fair. Some of them had traveled hundreds of miles to be there.

The company explained that the interviews has already been scheduled, many times weeks into the application process. Those unable to be interviewed were asked to email their resumes, according to several engineers who spoke with Reuters and who have backgrounds in mechanical, electrical, and chemical engineering.

SEE ALSO: Audi to Build Electric Q5 SUV in Mexico

Tesla had been recruiting assembly-line workers, but found it difficult to find the right engineering recruits. Silicon Valley is more of a marketplace for software engineers than those with a manufacturing background.

Mexican engineers remained positive about Tesla, even if barred from entering the Grand Fiesta Americana hotel’s meeting rooms. Some of them had about 20 years of experience, while others recently graduated from college.

“It’s a project that has a big future, these are the cars of the new era,” said Nadia Marrufo, a 22-year-old chemical engineer specializing in industrial processes.

Reuters