Danish politicians and citizens reacted with surprise and frustration Wednesday to the news that President Donald Trump had postponed a planned state visit to Denmark in response to its prime minister's rejection of his interest in buying Greenland, a Danish territory.

"It is with regret and surprise that I received the news" of Trump's cancelation, Prime Minister Mette Frederiksen said at a news conference, adding that the government's preparations had been "well underway."

"I was looking forward to having a dialogue on the many shared interests that Denmark has with U.S." she said, adding that those interests included developments in the Arctic, which "call for further cooperation between the U.S. and Greenland, Faroe Islands and Denmark."

“And therefore, I would like to underline our invitation for stronger cooperation on Arctic affairs still stands,” Frederiksen said. She added, however, that any potential sale of Greenland to the U.S. "has clearly been rejected."

Morten Østergaard, leader of Radikale Venstre, a center-left party in a ruling coalition with the Socialdemokratiet party, tweeted, "The reality is stranger than fiction. It shows why, more than ever, we should regard E.U. countries as our closest allies. The man is unreliable."

Both sides of the country's political spectrum were united in anger. "So Mr. Trump — you have now decided to postpone your visit to Denmark. Why not just cancel? We are so busy here with other things ..." wrote Søren Espersen, a member of Parliament for the populist right-wing Dansk Folkeparti.

One Danish lawmaker called on Trump to "show more respect."

As a Dane (and a conservative) it is very hard to believe. For no reason Trump assumes that (an autonomous) part of our country is for sale. Then insultingly cancels visit that everybody was preparing for.



Are parts of the US for sale? Alaska?



Please show more respect.

🇩🇰🇬🇱🇺🇸 — Rasmus Jarlov (@RasmusJarlov) August 21, 2019

Trump tweeted on Tuesday that he was postponing the trip, which had been planned for Sept. 2, after Frederiksen told reporters Monday on a visit to Greenland: "Greenland is not for sale. Greenland is not Danish. Greenland belongs to Greenland."

"Great friends & Allies like US and DK should be able to discuss all issues openly & candidly," tweeted U.S. ambassador to Denmark Carla Sands on Wednesday.

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Frederiksen told reporters Wednesday that the U.S. remained one of Denmark's closest allies. "We will of course, from Denmark, continue our ongoing dialogue with the U.S. on how we can develop our cooperation and deal with the many common challenges we are facing," she said.

Some Danes had been planning to greet Trump with a range of satirical protests — some of which are set to go ahead anyway.

Morten Skovgaard, a self-employed communications consultant living in Copenhagen, had been in the process of obtaining permits for the Trump "baby blimp" to fly over Copenhagen during a protest planned for Sept. 2. The 20-foot balloon depicting the president as an angry infant has been seen at protests in London and Washington.

Skovgaard said he still plans to fly the Trump effigy on Sept. 2 to channel disapproval of Trump and frustration at Denmark's recent reluctant foray into the global spotlight.

"When you encounter something absurd, meet it with absurdity," he said.

Skovgaard said Danes were struggling to understand how their country's relationship with an ally could have become so inconsistent.

"We love the U.S. We have a lot in common and have supported each other over the years. We will keep doing that. How is it possible for one man to flip in the media and jeopardize the entire relationship?" he said. "A lot of public debate today in Denmark is how we still have any normality in otherwise good relations we’ve had."

Light-up signs bearing the president's name were taken down Wednesday from two prime real-estate locations in Copenhagen's main square after the owner of the building enacted a clause in the contract, their funder told NBC News. "It has served its purpose," said Nicolai Oster, who splits his time between Denmark and Switzerland.

Oster emphasized that while he was "not a Trump fan," he had rented the signs to show support for the visit and counter "grown-up Danes behaving like kindergarten children toward the representative of our most important ally." He blames the visit being canceled on his government's response to Trump's interest in Greenland.

"The Danish government and politicians have from the beginning said, 'No, no, no, we are not engaging in any discussion and debate about the whole Greenland situation. ... Because it’s Trump, we will say no and make fun of him,'" Oster told NBC News.

"Why should he come? I understand him."