Denmark Prime Minister Mette Frederiksen said "you cannot spy against an ally" after reports that the U.S. was gathering intelligence on Greenland.

The Denmark prime minister's comments come a day after the top American diplomat in the country was summoned for an explanation of reports of U.S. intelligence gathering in Greenland.

He has said the U.S. will take control of Greenland eventually and has not ruled out military intervention, alarming American allies, particularly Denmark. The U.S. has a military