NATO Secretary-General Mark Rutte warned the European Union Monday that the alliance would not be able to defend itself without the United States' "nuclear umbrella" and military assistance, amid heightened tensions over Greenland.

Tensions in Europe escalated in recent weeks over President Donald Trump's threat to annex Greenland, which is a territory of NATO ally Denmark, but Trump has since backed off the threat of military force after creating the framework of an agreement to acquire Greenland last week. 

Rutte, who spoke with Trump at the World Economic Forum last week, told European lawmakers in Brussels that they would need to double their expected economic spending on defense if they hoped to defend themselves without the U.S.

“If anyone thinks here … that the European Union or Europe as a whole can defend itself without the U.S., keep on dreaming. You can’t,” Rutte said, according to the Associated Press. “If you really want to go it alone, forget that you can ever get there with 5%. It will be 10%. 

"You have to build up your own nuclear capability. That costs billions and billions of euros," he continued. "[Europe] would lose the ultimate guarantor of our freedom, which is the U.S. nuclear umbrella. So, hey, good luck!”

NATO leaders boosted their defense spending commitments in June to 3.5% of their GDP and an additional 1.5% on defense-related infrastructure by 2035. 

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.