The 79-year-old Republican has been clamoring for the United States to acquire Greenland, a large island territory of Denmark, citing what he called security threats from Russia and China in the Arctic Circle.

On Wednesday he announced a "framework" for a future deal on Greenland and the cancellation of planned tariffs on European countries that had opposed his moves to control the island -- but not before ruffling NATO allies and straining transatlantic relations.

"I'm helping NATO, and until the last few days, when I told them about Iceland, they loved me," Trump said during his remarks to the World Economic Forum meeting in Davos.

"They're not there for us on Iceland -- that I can tell you. I mean, our stock market took the first dip yesterday because of Iceland. So Iceland's already cost us a lot of money."

It seemed obvious he was referring to Greenland and not the smaller neighbouring Iceland, an island in the North Atlantic famous for its breathtaking volcanic landscapes.

After the speech, White House Press Secretary Karoline Leavitt pushed back against a post on X by a journalist, Libbey Dean, who wrote that "President Trump appeared to mix up Greenland and Iceland around three times."

"No he didn't, Libby. His written remarks referred to Greenland as a 'piece of ice' because that's what it is. You're the only one mixing anything up here," Leavitt fired back on X, misspelling the journalist's name.

During his speech at Davos, Trump, as he often does, frequently strayed from the written script scrolling on the teleprompters.

Asked about the events in Davos, Gavin Newsom, California's Democratic governor and a leading opposition figure in the United States who is considered a potential presidential candidate in 2028, seized on the moment.

"None of this is normal," Newsom said. "There's a normalisation, a deviancy of consciousness."

- Sensitive subject -

The issue of mental acuity is a sensitive one for Trump.

During the 2024 presidential campaign, he attacked incumbent Joe Biden, claiming the Democrat suffered from dementia.

In recent days, some Democratic lawmakers have called for invoking the US Constitution's 25th Amendment, which allows for removing a president who no longer has the physical or intellectual capacity to carry out the duties of office.

The politicians justified their calls by citing a message that Trump had sent to Norwegian Prime Minister Jonas Gahr Store.

In the message, made public on Monday, Trump expressed his displeasure with not being awarded last year's Nobel Peace Prize.

Trump also reiterated his desire for the US to take control of Greenland.

"Considering your Country decided not to give me the Nobel Peace Prize for having stopped 8 Wars PLUS, I no longer feel an obligation to think purely of Peace," Trump wrote.

However, an independent committee -- not the Norwegian government -- is the body that awards the peace prize and other Nobel prizes at an annual ceremony in Oslo.