The US will impose tariffs on "external" agricultural products from April 2, President Donald Trump said on social media, in his latest threat to erect trade barriers on imports. "To America's great farmers: get ready to start producing large quantities of agricultural products for sale within the United States," Mr. Trump said. "There will be tariffs on external products on April 2." Mr. Trump did not elaborate on which products would be affected or whether there would be exceptions. It was unclear whether his plan was part of a previously announced effort to impose so-called "reciprocal" tariffs on virtually all US trading partners.