Denmark said on Friday it meant seriously that Greenland is not for sale, after Secretary of State Marco Rubio said U.S. President Donald Trump's interest in acquiring the island was "not a joke".

Secretary of State Marco Rubio insisted that President Donald Trump’s talk about buying Greenland “is not a joke.” “This is not about acquiring land for the purpose of acquiring land,” Rubio said in an interview on Thursday with Megyn Kelly on SiriusXM.

Secretary of State Marco Rubio says President Donald Trump’s desire to acquire Greenland and retake control of the Panama Canal is driven by legitimate national security interests stemming from growing concerns about Chinese activity and influence in the Arctic and in Latin America.