Speaking alongside Turkish President Recep Tayyip Erdogan, Trump argued that the Arctic island was strategically important to US national security , citing the presence of Russian and Chinese ships in nearby waters.

"It was Greenland that, and it continues to be, that should be controlled by the United States, not by Denmark. And when they wouldn't go along with it, and with all the money we spent to help them with Russia, and we don't have to spend any money, we could remove all of our soldiers out of Europe," Trump said.

He also warned European allies to focus on immigration and energy policies.

"If they're not careful with those two things, you're not going to have a Europe anymore," he added.

Greenland is a self-governing territory within the Kingdom of Denmark. Both the Danish and Greenlandic governments have repeatedly rejected the idea of a US takeover, maintaining that the island's future should be determined by the people of Greenland.

Trump's remarks came as NATO leaders gathered in Ankara on July 7 and 8 to discuss defence spending, continued support for Ukraine and the future direction of the alliance.