U.S. ambassador to Denmark Ken Howery was summoned to the foreign ministry in Copenhagen on Monday after President Trump's newly appointed envoy for Greenland called for making the island part of the U.S., according to Danish officials.

Why it matters: The Danish government wasn't informed in advance about the appointment of Louisiana Gov. Jeff Landry as Greenland envoy, the officials said.

• It is not even clear whether the State Department knew about the appointment in advance of Trump's announcement on Sunday.
• Soon afterward, Landry said the mission of his part-time role was "to make Greenland a part of the U.S."
• Trump's appointment and Landry's statement renewed the tension between the U.S. and Denmark over Greenland after several months of calm.

Flashback: The president has for years desired the Arctic island, which governs itself as an autonomous territory within the Kingdom of Denmark.

• During his transition and the early months of his second term, Trump advocated for the Greenland acquisition, calling it a national security necessity.
• Leaders in Greenland and Copenhagen have consistently reminded him it's not for sale. In March, the president declined to take annexation by military force off the table.

Driving the news: In his Truth Social post on Sunday, Trump said Landry — who will remain as governor while taking on the envoy role — "understands how essential Greenland is to our National Security."

• Landry has previously backed Washington's push for jurisdiction over Greenland, writing in January: "We need to ensure that Greenland joins the United States."
• Danish Foreign Minister Lars Lokke Rasmussen said the appointment was unacceptable, stressed he was upset by Landry's comments, and summoned the U.S. ambassador in protest.

Behind the scenes: Danish officials said the appointment and Landry's remarks contradicted other messages they've received from U.S. officials over the last several months and as recently as two weeks ago.

• On December, a U.S. delegation headed by Acting Assistant Secretary of State Brendan Hanrahan visited Nuuk, Greeland for annual talks with officials from Denmark and Greenland.
• The appointment of a new envoy or a renewed push for U.S. control of Greenland weren't mentioned in those talks. If anything, the message was the opposite, sources with direct knowledge of the talks said.

• A Danish official said that while Denmark had been told by U.S. interlocutors for months that no new surprises were coming on Greenland, the Danish government had been "mentally prepared" for the possibility that wouldn't be the case.

What they're saying: Greenland's Prime Minister Jens-Frederik Nielsen said on Monday that while Trump's announcement may "sound significant," it changes nothing for "us here at home," according to a translation of his Facebook post.

• "Greenland belongs to the Greenlanders and its territorial integrity must be respected," he wrote.

The intrigue: Landry's surprise appointment has sparked questions in Louisiana about where this idea came from and whether he can legally take a government side gig, Axios New Orleans' Chelsea Brasted notes.

• A spokesperson for Landry did not immediately respond to a request for comment.
• Landry wrote on X that the job "in no way affects my position as Governor of Louisiana."