The US envoy to Denmark has been summoned for talks after reports at least three people with connections to President Donald Trump have been involved in covert influence operations in Greenland.

In a lengthy written statement, the US State Department confirmed the deputy chief of mission in Copenhagen, Mark Stroh, had met Danish foreign ministry officials.

It declined to comment “on the actions of private US citizens in Greenland.”

The department said Stroh had “a productive conversation and reaffirmed the strong ties among the government of Greenland, the United States, and Denmark”.

It said the US valued its relationships with both Denmark, a NATO ally, and Greenland and noted that Trump and his top aides had all said they respected “the right of the people of Greenland to determine their own future”.

“We continue to foster engagement and co-operation with Denmark and Greenland to support increased security and prosperity for our nations,” it said.

Stroh is the second American diplomat to be summoned by a European NATO ally this week as the Trump administration shakes up its approach to foreign policy. France had called US Ambassador Charles Kushner to its foreign ministry after he wrote to French President Emmanuel Macron alleging the country was doing too little to combat antisemitism.

The White House did not offer an immediate comment on Denmark’s summons.

Trump has repeatedly said he seeks US jurisdiction over Greenland, a vast, semi-autonomous territory of Denmark. He has not ruled out military force to take control of the mineral-rich, strategically located Arctic island.

Denmark and Greenland have said the island is not for sale and condemned reports of the US gathering intelligence there.

Donald Trump jr in Greenland earlier this year. Photo: AAP

Public broadcaster DR said Danish government and security sources that it didn’t name, as well as unidentified sources in Greenland and the US, believed that at least three American nationals with connections to Trump had been carrying out covert influence operations in the territory.

One of those people allegedly compiled a list of US-friendly Greenlanders, collected names of people opposed to Trump and got locals to point out cases that could be used to cast Denmark in a bad light in American media, the broadcaster reported. Two others have tried to nurture contacts with politicians, businesspeople and locals, according to the report.

DR said its story was based on information from eight sources, who believe the goal is to weaken relations with Denmark from within Greenlandic society.

The broadcaster said it had been unable to clarify whether the Americans were working at their own initiative or on orders. It said it knew their names but chose not to publish them.

The Associated Press could not independently confirm the report.

“We are aware that foreign actors continue to show an interest in Greenland and its position in the Kingdom of Denmark,” Danish Foreign Minister Lars Løkke Rasmussen said.

“It is therefore not surprising if we experience outside attempts to influence the future of the Kingdom in the time ahead.”

“Any attempt to interfere in the internal affairs of the Kingdom will of course be unacceptable.”