Trump fires a warning shot at GM: 'Make in USA or pay big border tax!'

President-elect Donald Trump said Tuesday that General Motors and other US companies could face a hefty tax if they ship manufacturing overseas. 

"General Motors is sending Mexican made model of Chevy Cruze to U.S. car dealers-tax free across border," Trump tweeted. "Make in U.S.A. or pay big border tax!"

Shares of the automaker slipped by about 1% in pre-market trading after the tweet. 

Since his election, Trump has persuaded several large companies to keep production and jobs in the US. The air-conditioner maker Carrier said that it would keep more than 1,000 jobs across two locations in Indiana, while the state will provide $700,000 in tax incentives. 

Late last year, a number of Trump's tweets about public companies were market-moving. He said the cost of Boeing's contract to build a new Air Force One was "exorbitant," sending the shares lower. His tweet calling for the US to expand its nuclear capability until the "world comes to its senses regarding nukes" spiked a uranium Exchange Traded Fund. 

Trump also commented that the cost of the F-35 fighting-jets program was out of control, sending shares of Lockheed Martin down 4% after the tweet.  

Trump said last month that he had sold all of his stocks in June.