Denmark has summoned the top US diplomat in Copenhagen after intelligence reports suggested that Americans linked to Donald Trump carried out a covert operation to promote the president's plan to take over Greenland.

State broadcaster DR said unnamed sources told them the Danish government believed at least three US citizens with ties to Trump's administration were involved in the mission.

Neither DR nor the Danish foreign ministry named the individuals mentioned in the reports.

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

He added: 'It is therefore not surprising if we experience outside attempts to influence the future of the Kingdom in the time ahead.'