Some officials in South Korea say agreeing to the pipeline investment might placate the U.S., but Trump is still threatening tariffs.

President Donald Trump pointed to South Korea as a country with more unfair tariffs against American products than China, while slamming the handing out of subsidies for foreign chipmakers like Samsung Electronics Co.

Japan, South Korea and other countries want to partner with the United States in a "gigantic" natural gas pipeline in Alaska, U.S. President Donald Trump said on Tuesday, claiming they would invest "trillions of dollars each.