Trump says he will increase tariffs on South Korea to 25%

President Trump threatened to increase tariffs on South Korean exports because the country did not ratify a trade agreement with the United States quickly enough.

In a post on Truth Social, Mr. Trump accused Korea’s National Assembly of failing to approve a trade deal he struck with South Korea’s president on July 30.

“Because the Korean legislature has not enacted our historic trade agreement, which is its prerogative, I hereby increase South Korea’s tariffs on automobiles, lumber, pharmaceuticals and all other reciprocal tariffs from 15% to 25%,” the president said.

As of Monday evening, the White House had not yet issued an executive order enacting the tariff change.

The president imposed a 25 percent tariff on all South Korean exports last year. He then agreed to cut that to 15 percent in a framework trade deal he announced with President Lee Jae Myung in July. But the two governments continued to argue over the details of the agreement, including a commitment by South Korea to invest in the United States. While the United States wanted a cash investment of hundreds of billions of dollars, Korean officials feared that a deal of that size was not economically possible.

The Korean government confirmed in October that it had reached an agreement with the United States on the details of the deal after Trump visited the country that month. As part of the agreement, they agreed to invest up to $20 billion per year and provide an additional $150 billion to invest in American shipbuilding operations.

To implement the trade agreement, South Korea had to pass the law through its National Assembly.

The Trump administration has announced limited trade deals with more than 10 countries, but some of those deals have run into trouble. For example, a trade deal negotiated with the European Union was recently put on hold after Mr. Trump threatened European nations with tariffs unless they gave up Danish territory in Greenland to the United States. Although Mr. Trump later backed away from that tariff threat, the trade deal still requires approval from the European Parliament.

The legal authority Mr. Trump relied on to impose tariffs on South Korea and other nations, a 1970s emergency law known as the International Economic Emergency Powers Act, is currently under review by the Supreme Court.

The court is expected to make a decision in the coming months on whether Mr. Trump exceeded his authority by using that law to impose tariffs around the world. If he is found to have acted unlawfully, the president may have to rely on other tariff laws that do not allow him to raise and lower tariffs so suddenly.