President Donald Trump said he would send letters to trading partners in about two weeks, informing them that the US was imposing unilateral tariffs on them.

Speaking to reporters at the Kennedy Center in Washington, D.C., on Wednesday, the president said he did not think extending the deadline for trade talks with countries was necessary, as he had already made a "great deal with China," and one with the UK.

"Now, at a certain point, we're just going to send letters out, and I think you understand that, saying this is the deal. You can take it, or you can leave it," Trump said.

He added, "You don't have to use it. You don't have to shop in the United States, as I say."

He said trade negotiations were still ongoing with about 15 countries, including Japan and South Korea, but it was not possible to negotiate with "150 plus" countries.

His comments on imposing unilateral tariffs came about 60 days into the 90-day tariff pause he announced in April.

On April 2, the president announced a baseline 10% tariff on goods from all countries. Some regions would be subject to even higher levies, which he dubbed "reciprocal tariffs," like the European Union with 20% and Vietnam with 46%.

On April 9, he said the "reciprocal" tariffs would be delayed for 90 days to allow for trade negotiations. During the pause, levy rates were dropped to 10% for goods from most countries.

On April 23, Trump said he would start imposing tariffs on countries that don't reach trade deals with the US within two to three weeks.

Trump's comments at the Kennedy Center come shortly after the US Court of Appeals for the Federal Circuit announced on Tuesday that the tariffs would be allowed to stay in effect for at least the next two months, halting a lower court ruling that invalidated them.

Representatives for Trump did not respond to a request for comment from Business Insider.