Denmark’s foreign minister has summoned the chief U.S. diplomat in Copenhagen over reports that several American citizens were conducting an influence operation in Greenland.

Foreign Minister Lars Lokke Rasmussen said any attempt to covertly influence the internal affairs of the kingdom of Denmark would be unacceptable.

“We live in transparent democracies, and if someone thinks that they can influence it with methods where they try to induce fifth column activities or that kind of activity, then it is contrary to the way in which states cooperate with each other, and this must of course be denounced,” Mr. Rasmussen said Wednesday at a press conference.

Since the U.S. currently has no ambassador in Copenhagen, Mr. Rasmussen summoned charge d’affaires Mark Stroh, who has been in Denmark since June.

Danish public broadcaster DR reported Wednesday what it called an American covert operation aimed at infiltrating and influencing Greenland society to promote secession from Denmark.

The DR report said at least three Americans have been operating in Greenland since the start of the year and have maintained contacts with politicians, business people and citizens. The report, which cited unnamed Danish, Greenland and U.S. officials, said journalists were unable to determine if the three Americans were working independently or for the U.S. government.

One of the men traveled to Greenland’s capital, Nuuk, and collected a list of individuals who support President Trump, the report said. An anonymous source told DR that the people mentioned in the list would form the base of a secessionist party in Greenland.

Since taking office, Mr. Trump has repeatedly asserted he wants the U.S. to annex Greenland, citing economic and security concerns. Greenlanders and the Danish government, which controls Greenland’s foreign policy, have soundly rejected calls for U.S. dominance of the Arctic island.

The Washington Times has contacted the State Department and the U.S. Embassy in Copenhagen for comment.

This is the second time Denmark has summoned Mr. Stroh this year over concerns of U.S. influence operations inside of Greenland. In May, Mr. Rasmussen summoned the charge d’affaires following a report that found U.S. spy agencies were directed to focus on Greenland.

According to the May report, first detailed by the Wall Street Journal, U.S. spy agencies had been directed to gather information about Greenland independence movements and how citizens felt about U.S. involvement in the country’s affairs.

• Vaughn Cockayne can be reached at vcockayne@washingtontimes.com.