The United Kingdom's Prime Minister Keir Starmer has said the United States' threat to impose tariffs on several European countries for their backing of Denmark in the territorial dispute with the US over Greenland is "completely wrong" and that using economic pressure as a weapon against allies cannot be justified.

The US has recently become more vocal in its desire to take control of Greenland, a sparsely-populated but mineral-rich island on the edge of the Arctic Circle that is a Danish territory, citing national security concerns, and its messages to a fellow member of the NATO military alliance and long-standing ally have become increasingly threatening.

The foreign ministers of Denmark and Greenland attended talks at the White House in the US capital Washington last week, but Denmark's Foreign Minister Lars Lokke Rasmussen later said a "fundamental disagreement" remained, and several European countries, including France, Germany, the Netherlands and United Kingdom, have sent small numbers of military personnel to Greenland as a gesture of solidarity.

During the weekend, Trump announced that from next month, imports from the countries supporting Denmark will be subject to 10 percent tariffs, rising to 25 percent later in the year, which would remain until "such time as a deal is reached for the complete and total purchase of Greenland".

The move has drawn international condemnation and stirred up the prospect of a trade war, in addition to potentially causing a rift in NATO, and Starmer said the correct way to deal with disagreements between allies was "calm discussion".

"Greenland matters. The High North will require greater investment and stronger collective defense. The US will be central to that effort, and the UK stands ready to contribute," he said. "But there is a principle here that cannot be set aside. Any decision about the future status of Greenland belongs to the people of Greenland and the kingdom of Denmark alone. That right is fundamental, and we support it … alliances endure because they are built on respect and partnership, not pressure."

When asked by a reporter if he would be willing to impose retaliatory tariffs, Starmer said: "A tariff war is in nobody's interests. We have not got to that stage, my focus is making sure we don't get to that stage."

One of Trump's justifications for seeking control of Greenland, which is in a strategically significant position, is that otherwise Russia or China will seek to do so, despite the Danish government confirming there is no significant Chinese investment in the region.

China's Foreign Ministry spokesperson Guo Jiakun said: "We urge the US to stop using the so-called 'China threat' as an excuse to pursue its own interests."

In another development, a letter has been published, sent by Trump to Norway's Prime Minister Jonas Gahr Store, in which he says that having not been awarded the Nobel Peace Prize – an award that is not controlled by the Norwegian government – means "I no longer feel an obligation to think purely of peace", adding "the world is not secure unless we have complete and total control of Greenland".

The peace prize is awarded by a committee appointed by the Norwegian parliament, not the country itself.