(CNN) President Donald Trump suggested Wednesday that if tariffs had been placed on more foreign-made vehicles, American automobile giant General Motors would not have had to close plants in the United States.

"The reason that the small truck business in the US is such a go to favorite is that, for many years, Tariffs of 25% have been put on small trucks coming into our country. It is called the 'chicken tax.' If we did that with cars coming in, many more cars would be built here [...] and G.M. would not be closing their plants in Ohio, Michigan & Maryland. Get smart Congress. Also, the countries that send us cars have taken advantage of the U.S. for decades. The President has great power on this issue - Because of the G.M. event, it is being studied now!" Trump tweeted.

What's the 'chicken tax'?

The 'chicken tax' or 'chicken tariff' the President mentioned in his tweet was imposed by the US in the 1960s in response to a tariff by some European countries on American poultry exports. It sparked tariffs on foreign-made brandy, dextrin, potato starch and vehicles -- specifically, light trucks, such as pickups.

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