President Donald Trump sent out letters to nations that haven't entered into trade agreements with the U.S., informing them of their new tariff rates.

The U.S. will put in place a 25% tariffs on imports from Japan and South Korea starting on Aug. 1, according to letters posted by President Donald Trump on his social media platform on Monday. Trump already delayed the high tariff rates against dozens of U.S. trade partners that he rolled out on April 2 until Wednesday.

While South Korean imports to the U.S. face 25% tariffs, the same as Trump promised in April, the rate on Japan has been raised by 1 percentage point to 25%.

The Trump administration has again delayed the date when new reciprocal tariffs will go into effect, and the president threatened a 35 percent tariff on Canada.

In letters so far to 14 countries, including smaller exporters to the United States such as Serbia, Thailand and Tunisia, Trump hinted at opportunities for additional negotiations, even while warning that reprisals would draw a like-for-like response.

Trump shared screenshots of letters detailing new tariff rates for over a dozen countries, allowing room for further negotiations before the renewed deadline of Aug. 1.

Trump Always Chickens Out—JPMorgan CEO Jamie Dimon cautioned that investors may be underestimating the risks of relying on past tariff U-turns. UBS’s Paul Donovan reinforced this concern in a note seen by Fortune,

President Donald Trump issued separate letters to the president of South Korea and Japan's prime minister on Monday, saying the U.S. will start charging a 25% tariff on Aug. 1.