Denmark’s Prime Minister Mette Frederiksen remarked on Friday that “you cannot spy against an ally” following reports of the U.S. gathering intelligence on Greenland. This comes amidst U.S. President Donald Trump’s continued proposal to purchase the Arctic island.

Frederiksen told The Associated Press, “Cooperation on defense, deterrence, and security in Northern Europe is becoming increasingly significant. Naturally, you cannot spy against an ally.”

These statements were made as Denmark and Greenland resist Trump’s ambitions to acquire the autonomous Danish territory, emphasizing that it is not for sale. Despite Denmark being a NATO ally, Trump has not dismissed the possibility of using military force to obtain it.

Officials under the U.S. director of national intelligence, Tulsi Gabbard, directed intelligence agency heads to collect information on Greenland’s independence movement and views about U.S. resource extraction. (Getty Images)

Gabbard’s office released a statement saying she had made three “criminal” referrals to the U.S. Justice Department over intelligence community leaks in response to the report from The Wall Street Journal, which cited two sources familiar with the matter.

“The Wall Street Journal should be ashamed of aiding deep state actors who seek to undermine the President by politicizing and leaking classified information,” Gabbard said. “They are breaking the law and undermining our nation’s security and democracy. Those who leak classified information will be found and held accountable to the fullest extent of the law.”

The Associated Press contributed to this report.