The United States is exerting "unacceptable pressure" on Greenland, Danish Prime Minister Mette Frederiksen said on Tuesday, ahead of an unsolicited visit by a high-profile U.S. delegation to the semi-autonomous Danish territory this week.

The visit to an American military base and a dog sled race will be led by Usha Vance, wife of U.S. Vice-President J.D. Vance, and includes White House National Security Adviser Mike Waltz and Energy Secretary Chris Wright. It runs from Thursday to Saturday. The vice-president later said that he will also visit Greenland, with plans to be there on Friday.

U.S. President Donald Trump on Monday reiterated his suggestion that the U.S. should take over Greenland, saying the vast island was important for U.S. national security. Frederiksen has rejected the proposal, saying it is up to the people of Greenland to decide their future.

"I have to say that it is unacceptable pressure being placed on Greenland and Denmark in this situation. And it is pressure that we will resist," she told Danish broadcasters DR and TV2.

Greenland's acting head of government, Múte Egede, has labelled the visit a "provocation," as it coincides with government coalition talks and municipal elections scheduled for the following week.

"This is a charm offensive without the charm," said Noa Redington, an analyst and former adviser to previous Danish prime minister Helle Thorning-Schmidt.

"And everyone is upset because it's so obvious that this is about intimidating the Greenlandic people and provoking Denmark."

WATCH | U.S. visit a 'provocation,' PM says:

Greenland PM calls U.S. delegation’s visit a provocation

With U.S. President Donald Trump threatening to take over Greenland, the country’s prime minister has called a visit by a U.S. delegation a provocation and highly aggressive. The Americans on the trip include national security adviser Mike Waltz and Usha Vance, the vice-president’s wife.  

'Strong signal of respect'

Since Donald Trump Jr.'s private visit to the mineral-rich island in January, the U.S. president has consistently discussed annexation of Greenland and urged Greenlanders to join the United States.

Polls have shown that nearly all Greenlanders oppose joining the U.S.

Earlier this month, anti-American protesters gathered in the capital Nuuk and in several other towns across the island, in some of the largest demonstrations ever seen in Greenland.

On Monday, Trump said that his administration was working with "people in Greenland" who want something to happen, but did not elaborate.

Kuno Fencker welcomed the visit, saying it was "an honour and a strong signal of respect." Fencker is a member of Greenland's parliament for the nationalist and strongly pro-independence Naleraq party, which came in second in a March 11 general election,

"They are welcome in Greenland," he said, adding that he had not been in contact with the U.S. administration about the visit.

Brian Hughes, spokesperson for the White House National Security Council, said the delegation aimed to "learn about Greenland, its culture, history and people."

'He wants Greenland'

Frederiksen disputed the notion of a private visit with official representatives.

"The visit is clearly not about what Greenland needs or wants," said Frederiksen. "President Trump is serious. He wants Greenland. Therefore, [this visit] cannot be seen independently of anything else."

She said Denmark did not oppose ties with the United States, citing a 1951 bilateral agreement that established U.S. rights to move freely and construct military bases in Greenland, given Denmark and Greenland are notified.

"We are allies," she said. "There is no indication either in Denmark or Greenland that we do not want co-operation with the Americans."

Egede has called for more robust support from allies against the U.S.

Frederiksen said, "There is massive support from the Nordic countries and the EU, so we have our allies and close partners with us."