NATO chief Mark Rutte warned Monday that Europe cannot defend itself without the United States, pushing back against renewed calls for the continent to stand on its own after tensions rose over Greenland.

"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. We can't. We need each other," he said during his address at the European Parliament's Committee on Foreign Affairs and Committee on Security and Defense in Brussels.

He added that the U.S. also relies on NATO to ensure its own security, emphasizing the mutual dependence among NATO allies.

"If you really want to go it alone, and those who you are pleading for that, forget that, you can never get there with 5%, it will be 10%.

"You have to build up your own nuclear capability that costs billions and billions of euros. You will lose, then, in that scenario, you would lose the ultimate guarantor of our freedom, which is the U.S. nuclear umbrella. So, hey, good luck," he added.

Rutte emphasized the need for close coordination between NATO and the EU, while acknowledging their respective strengths.

"The EU is great in resilience, but the EU is also great when it comes to regulation. And here, we need particularly deregulation," he said.

Greenland

His remarks come amid lingering tensions over Greenland, following U.S. President Donald Trump's controversial bid to acquire the Danish territory.

Trump softened his tone after meeting with Rutte in Davos, Switzerland, announcing that they discussed a framework deal on Greenland that would address his security concerns and counter Russian and Chinese influence.

Rutte said the two workstreams agreed on Greenland and Arctic security, with one focusing on NATO taking a more active role in determining how the alliance can collectively prevent Russia and China from increasing their presence in the Arctic region.

The second workstream is between Denmark, Greenland, and the U.S., he noted, saying: "It is up to the Danes, Greenland and the U.S. to do that. I will not be involved in that work stream."

"I have no mandate to negotiate on behalf of Denmark, so I didn't, and I will not," he added.

Ukraine

On the ongoing Moscow-Kyiv war, Rutte stressed that while Europe's defense industry and internal market are key strengths, the immediate priority should be meeting Ukraine's urgent defense needs amid ongoing attacks on "civilian infrastructure."

"The EU is doing vital work here with this €90 billion ($107 billion) loan package. 90 billion, which will make a massive difference to Ukraine's security, it will make a massive difference to Ukraine's prosperity. But here, I would really strongly urge you to ensure flexibility in how these funds can be spent," he said.

"Europe is now building its defense industry, and that is vital, but it cannot at the moment provide nearly enough of what Ukraine needs to defend itself today and to deter tomorrow. So, as you take this loan forward, please, I encourage you to keep Ukraine's needs first in focus," he added.

He highlighted the critical role of U.S. support in keeping Ukraine in the fight, noting that billions of dollars' worth of American military hardware are already flowing into the country.