A woman is reflected on a screen showing Toyota Motor Corp's Prius hybrid car at the company's showroom in Tokyo, June 14, 2016. REUTERS/Toru Hanai

During his campaign that got him elected as the next president of the United States, Donald Trump often spoke about how he would keep jobs in the country. And even before taking office, he seems to be trying to do that using his favorite weapon: Twitter.

He has publicly attacked and tried to shame numerous companies in the last one month, referring to negotiations regarding their plans to open plants in or move jobs to other countries, on his Twitter account. The list includes air conditioner manufacturer Carrier, air plane makers Boeing and Lockheed Martin, as well as automaker General Motors. He also routinely targeted Ford Motor while on the campaign trail.

And in a tweet Thursday, Trump picked on another automaker, this time a non-U.S. company.

Toyota Motor Corp., the world’s largest automaker, has manufacturing plants in many places across the world. Its vehicles made in Mexico account for less than 10 percent of its sales in the U.S., according to estimates. Along with other Japanese car manufacturers — Honda, Mazda and Nissan — it produced about 1.4 million vehicles in Mexico in the financial year ended March 2016, and production is planned to be ramped up to 1.9 million vehicles by 2019, according to Japan External Trade Organization.

However, the total production in Mexico is only a fraction of the number of cars the same companies produce in the U.S. The top three Japanese automakers produced about 4 million vehicles in the U.S. in 2015, Reuters reported.

And according to estimates by JP Morgan, an increase in tariffs on cars imported from Mexico will have an impact of only about 0.7 percent on the operating profit of Toyota. None of the Japanese automakers have any plans to change their operations, at least as of now.

But the stock market still punished Toyota, whose shares dropped 1.69 percent on the Tokyo Stock Exchange during Friday trade. Its ADR shares traded on the New York Stock Exchange were lower by 0.57 percent during trade Thursday and fell another 0.42 percent after hours.