The US envoy to Denmark was summoned by the Danish foreign ministry on Wednesday after the country’s public broadcaster reported that a number of American men had attempted to conduct “influence operations” in Greenland.

According to an investigation by Danish public broadcaster DR, at least three Americans with “ties” to US President Donald Trump are conducting active operations in Greenland, sparking concerns that they could be working to shift public opinion and push Trump’s desire to make Greenland a part of the US.

Greenland, a huge, resource-rich island in the Atlantic, is a self-governing territory of Denmark. Trump has repeatedly stated that he wants to annex the island, claiming that this is needed for security purposes. Both Greenland and Denmark are staunchly opposed to the idea.

According to the DR investigation, which was based off conversations with eight sources across Denmark, Greenland and the US, the three men are conducting the operations in an attempt to “infiltrate Greenlandic society.”

One of the American men involved has made a list of Trump supporters in Greenland, with the goal of later recruiting them to establish a secessionist movement on the island, according to the broadcaster.

Greendland yearns for freedom.