US President Donald Trump backed down Wednesday on threats to seize Greenland by force from ally Denmark, announcing a vague deal aimed at ensuring security of the Arctic territory.

Trump cast his retreat -- also lifting the promise of sanctions against European nations that spoke out against the threats to Denmark -- as a win, saying the deal gives Washington "everything we wanted".

The agreement, he told reporters at the World Economic Forum in Davos, was negotiated with NATO Secretary-General Mark Rutte and would last "forever".

"I think it puts everybody in a really good position, especially as it pertains to security, and minerals and everything else," Trump said, hours after a speech in which he appeared to remove the threat of force to seize Greenland.

However, there was no sign that Trump had succeeded in his repeated vow to make Greenland part of the United States.