Denmark sent private messages in recent days to President-elect Trump's team expressing willingness to discuss boosting security in Greenland or increasing the U.S. military presence on the island, two sources with knowledge of the issue tell Axios.

Denmark acknowledged Thursday that it had long neglected the defense of Greenland, a vast and strategically important Arctic island - and one that U.S. President-elect Donald Trump has called vital for U.S. security.

Greenland's prime minister said he hasn't spoken to President-elect Donald Trump, but that he's open to discussions about what "unites us."