Aug. 21 (UPI) -- President Donald Trump has postponed a trip to Denmark to meet with its prime minister because the Danish government won't sell Greenland to the United States.
Trump was scheduled to travel to Copenhagen next month to meet with Prime Minister Mette Frederiksen and Greenland Prime Minister Kim Kielsen.
For weeks, it's been reported that Trump inquired about buying Greenland -- a largely autonomous nation technically under Danish ownership -- and Denmark's refusal is at the heart of the canceled September visit.
"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 tweeted. "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."
Later in the day, Trump was more critical of Frederiksen's response, calling her statement "nasty."
"It was not a nice way of doing it. She could have just said, 'no, we'd rather not do it,'" Trump told reporters gathered on the South Lawn.
"You don't talk to the United States that way, at least under me."
Trump has pursued the buy as a "large real estate deal" and said, "strategically it's interesting." Experts believe Greenland's vast natural resources are the primary reason for his interest.
"It's something we talked about," Trump said last weekend. "Denmark essentially owns it, we're very good allies with Denmark."
Frederiksen told Sermitsiaq, "Greenland is not for sale. Greenland is not Danish. Greenland belongs to Greenland."
Former Danish officials slammed Trump's sudden change of plans Wednesday.
"Total chaos with [Trump] and the cancellation of the state visit to Denmark," former Prime Minister Kristian Jensen tweeted. "It has gone from a big opportunity for strengthened dialogue between allies to a diplomatic crisis. Everyone should know Greenland is not for sale."
Former Foreign Minister Martin Ledegaard characterized Trump's response as "grotesque" and "a hissy fit."
Greenland's foreign ministry also rejected the idea in a tweet.
"Greenland is rich in valuable resources such as minerals, the purest water and ice, fish stocks, seafood, renewable energy and is a new frontier for adventure tourism," Greenland's foreign minister said. "We're open for business, not for sale."
Trump and first lady Melania Trump were supposed to visit Danish Queen Margrethe II and conduct bilateral meetings with business leaders.
The Danish Royal House was surprised by Trump's postponement.
"This has never happened before," Danish Royal House Director of Communications Lene Balleby told CNN.