Denmark’s foreign minister summoned the top US diplomat in the country over intelligence reports that US citizens have been conducting covert influence operations in Greenland.

At least three people with connections to Donald Trump’s administration have been working to infiltrate the semi-autonomous territory and promote its secession from Denmark to the US, according to the Danish public broadcaster DR, citing sources.

Lars Lokke Rasmussen, Denmark’s foreign minister, said in a statement: “We are aware that foreign actors continue to show an interest in Greenland and its position in the Kingdom of Denmark.

Without naming the individuals involved, he added: “It is therefore not surprising if we experience outside attempts to influence the future of the Kingdom in the time ahead.”

Mr Trump has picked the PayPal co-founder Ken Howery as the new US ambassador to Denmark, but the US mission in Copenhagen is currently led by Mark Stroh, the charge d’affaires.

Mr Trump has insisted Washington should take control of the resource-rich and strategically located territory for reasons of national and international security, and has not ruled out the use of force.