U.S. President Donald Trump has again said that the U.S. needs Greenland and that Denmark cannot be relied upon to protect the island.

The remarks, which came after a high-stakes meeting among U.S., Danish and Greenlandic officials, indicate that there are still fundamental differences among Washington, Copenhagen and Nuuk on the island's political future.

"Greenland is very important for national security, including that of Denmark," Trump told reporters in the Oval Office.