President Trump, like former President Harry S Truman before him, expressed interest in buying Greenland from Denmark.

But unlike when Truman was in office, some top Danish officials mocked the American president for even suggesting the notion.

Prime Minister Mette Frederiksen called the idea “absurd.”

“It’s an absurd discussion, and [Greenland Premier] Kim Kielsen has of course made it clear that Greenland is not for sale. That’s where the conversation ends,” she said.

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“Thankfully, the time where you buy and sell other countries and populations is over. Let’s leave it there. Jokes aside, we will of course love to have an even closer strategic relationship with the United States,” Frederiksen said. “Greenland is not for sale. Greenland is not Danish. Greenland belongs to Greenland. I strongly hope that this is not meant seriously,” Frederiksen said.

Then Trump canceled his plan visit to Denmark, set to occur Sept. 2.

“Denmark is a very special country with incredible people, but based on Prime Minister Mette Frederiksen’s comments, that she would have no interest in discussing the purchase of Greenland, I will be postponing our meeting scheduled in two weeks for another time,” Trump wrote Tuesday on Twitter. “The Prime Minister was able to save a great deal of expense and effort for both the United States and Denmark by being so direct. I thank her for that and look forward to rescheduling sometime in the future!”

Then Danish officials blasted Trump for what they felt was a disrespectful move.

See: Top Danish Official Disses Trump, Then Is Shocked When He Cancels Planned Trip There

Then Trump had had enough.

“I thought that the prime’s statement that it was absurd, that it was an absurd idea was nasty,” Trump said Wednesday on the White House lawn before departing for Kentucky to attend a veterans event. “They can’t say ‘how absurd.’

“I thought it was an inappropriate statement. All she had to do is say no, we wouldn’t be interested,” he said. “She’s not talking to me. She’s talking to the United States of America. You don’t talk to the United States that way, at least under me.”

Then Trump doubled down, taking to Twitter to slap Denmark.

“For the record, Denmark is only at 1.35% of GDP for NATO spending. They are a wealthy country and should be at 2%. We protect Europe and yet, only 8 of the 28 NATO countries are at the 2% mark. The United States is at a much, much higher level than that,” he wrote.

“Because of me, these countries have agreed to pay ONE HUNDRED BILLION DOLLARS more – but still way short of what they should pay for the incredible military protection provided. Sorry!” he wrote.