For years, the U.S. government has urged China to show "restraint" in pushing its claim on Taiwan and to drop military threats to bring the democratically governed island under its control.

Observers doubt the new US president will buy the world's largest island but his interest underlines its strategic importance President Donald Trump's claim that US ownership and control of Greenland is "an absolute necessity" has underlined the strategic importance of the world's largest island in terms of American missile defences and anti-submarine operations.

Greenland residents "want to be with us," Trump told reporters Saturday on presidential aircraft Air Force One.