Tensions around the sovereignty of Greenland have been stoked again after the territory's government rebuked a United States company.

The criticism came after the oil company, with alleged ties to US President Donald Trump, unloaded exploratory drilling equipment without the necessary approval.

The incident followed Trump's claims earlier this year that the US would assume control of the semiautonomous mineral-rich Danish territory that is home to 57,000 people.

The US president's designs on the 2-million-square-kilometer Arctic island drew condemnation from NATO countries that said both Denmark and the US are members of the military alliance and that a dispute between them would threaten its existence.

After a period of relative calm, the latest chapter began late last month when Texas-based Greenland Energy moved machinery onto the island's remote East Coast, causing Greenland's government to issue a "strong warning" through its Mineral Resources Authority in which it said: "All future logistical matters must be advised and approved by the Mineral Resources Authority — before they are carried out."