President Donald Trump on Monday set a 25% tax on goods imported from Japan and South Korea, as well as new tariff rates on Malaysia, Kazakhstan, South Africa, Laos and Myanmar, all of which would go into effect on Aug. 1.

Trump provided notice by posting letters on Truth Social that were addressed to the leaders of the various countries. The letters warned them to not retaliate by increasing their own import taxes, or else the Trump administration would further increase tariffs.

“If for any reason you decide to raise your Tariffs, then, whatever the number you choose to raise them by, will be added onto the 25% that we charge,” Trump wrote in the letters to Japanese Prime Minister Shigeru Ishiba and South Korean President Lee Jae-myung.

Imports from Malaysia would be taxed at 25%, Myanmar at 40%, Laos at 40%, South Africa at 30% and Kazakhstan at 25%. Trump placed the word “only” before revealing the rate in his letters to the foreign leaders, implying that he was being generous with his tariffs.

White House press secretary Karoline Leavitt indicated at a news briefing that similar letters to approximately five other countries also would be issued on Monday.

The letters are not agreed-to settlements but Trump’s own choice on rates, a sign that the closed-door talks with foreign delegations failed to produce satisfactory results for either side. Leavitt said that Trump was by setting the rates himself creating “tailor-made trade plans for each and every country on this planet and that’s what this administration continues to be focused on.”

Wendy Cutler, vice president of the Asia Society Policy Institute who formerly worked in the office of the U.S. Trade Representative, said the tariff hikes on Japan and South Korea were “unfortunate.”

“Both have been close partners on economic security matters and have a lot to offer the United States on priority matters like shipbuilding, semiconductors, critical minerals and energy cooperation,” Cutler said. “Moreover, companies from both countries have made significant manufacturing investments in the U.S. in recent years, bringing high-paying jobs to U.S. workers and benefiting communities all around the country.”

Trump still has outstanding differences on trade with the European Union and India, among other trading partners. Tougher talks with China are on a longer time horizon in which imports from that nation are being taxed at 55%.

Administration officials have said Trump is relying on tariff revenues to help offset the tax cuts he signed into law on Friday, a move that could shift a greater share of the federal tax burden onto the middle class and poor as importers would likely pass along much of the cost of the tariffs. Trump has warned major retailers such as Walmart to simply “eat” the higher costs, instead of increasing prices in ways that could intensify inflation.

Josh Lipsky, chair of international economics at The Atlantic Council, said that a three-week delay in imposing the tariffs was unlikely sufficient for meaningful talks to take place.

“I take it as a signal that he is serious about most of these tariffs and it’s not all a negotiating posture,” Lipsky said.

Trump’s team promised 90 deals in 90 days, but his negotiations so far have produced only two trade frameworks.