"This is in our national interest and it needs to be solved," Rubio said. Greenland's prime minister has repeatedly said the island is not for sale.

The secretary of State said purchasing the Danish territory is important to the country’s national interests in the Arctic.

Situated along major shipping routes through the Arctic, Greenland occupies a strategic trade and military position as nations, especially Russia, increase their military presence in the region. The potential for significant oil and gas reserves have been identified by the U.

Secretary of State Marco Rubio said on Thursday that President Donald Trump's offer to buy Greenland is “not a joke”, adding that acquiring the semi-autonomous Danish territory was in the US “national interest”.