European leaders on Sunday hit back at US President Donald Trump's threat of tariffs over their opposition to his designs on Greenland, with far-right Italian leader Giorgia Meloni urging Washington against making a "mistake".

Trump has made no secret of his desire to seize the vast Arctic island, an autonomous territory of Denmark, since returning to the White House for a second term, and a ramping up of this claim in recent weeks has deeply shaken transatlantic relations.

He again upped the ante on Saturday, threatening to punish eight European countries with tariffs after they sent a few dozen troops to Greenland as part of a military drill.

Meloni, who has a good relationship with Trump, said she had told him it was a "mistake" to punish Europe economically.

"I believe that imposing new sanctions today would be a mistake," she told journalists during a trip to Seoul, adding that "I spoke to Donald Trump a few hours ago and told him what I think."

However, Meloni also sought to downplay the conflict, telling journalists "there has been a problem of understanding and communication" between Europe and the United States on Greenland.

She said it was up to Nato to take an active role in the growing crisis.

British Prime Minister Keir Starmer is planning to discuss the situation with Trump "at the earliest opportunity", UK Culture Minister Lisa Nandy told the BBC, calling the president's tariff threat "wrong".

"We believe it's deeply unhelpful, and we believe it's counterproductive, and the prime minister has not shied away from making that clear," she said.

French President Emmanuel Macron meanwhile called on the European Union to combat the threatened tariffs by deploying its powerful "anti-coercion instrument".

That weapon — never used before and dubbed the EU's trade "bazooka" — allows for curbing imports of goods and services.

Trump has threatened to impose a 10-percent tariff from February 1 on all goods sent to the United States from Denmark, Norway, Sweden, France, Germany, the United Kingdom, the Netherlands and Finland.

That levy would then be increased to 25 percent on June 1 "until such time as a deal is reached for the complete and total purchase of Greenland", the US president said. (AFP)