Nato secretary general Mark Rutte on Monday warned that Europe cannot defend itself without the United States, pushing back against growing calls for the continent to reduce its military dependence on Washington amid rising transatlantic tensions.Addressing lawmakers at the European Parliament, Rutte dismissed the idea of Europe standing alone militarily. “If anyone thinks here again, that the European Union, or Europe as a whole, can defend itself without the US – keep on dreaming. You can’t,” he said.His remarks come as US President Donald Trump has been aggressively asserting to seize Greenland, an autonomous Danish territory, unsettling European allies before toning down the rhetoric following talks with Rutte last week. The episode reignited debate in Europe over strategic autonomy and reliance on US security guarantees. Rutte warned that without Washington, Europe would lose “the ultimate guarantor of our freedom, which is the US nuclear umbrella”. He said EU countries would need to more than double defence spending from the five percent NATO target agreed last year to 10 percent, and spend “billions and billions” on building nuclear arms. “So hey, good luck,” he added.France’s foreign minister Jean-Noel Barrot responded by saying Europe should take charge of its own defence. Posting on X, he said: “Europeans can and must take responsibility for their own security.”Rutte, however, insisted that US commitment to Nato’s article five mutual defence clause remained “total”, while making clear that Washington expects Europe to step up military spending. “They need a secure Euro-Atlantic, and they also need a secure Europe. So the US has every interest in Nato,” he said.The Nato chief reiterated praise for Trump’s pressure on European allies to increase defence budgets and appeared to reject proposals for a standalone European defence force to replace US troops, an idea floated earlier this month by EU defence commissioner Andrius Kubilius.“It will make things more complicated. I think Putin will love it. So think again,” Rutte said.On Greenland, Rutte said he and Trump agreed Nato should “take more responsibility for the defence of the Arctic”, but stressed that any negotiations over US presence on the island were a matter for Greenlandic and Danish authorities. “I have no mandate to negotiate on behalf of Denmark, so I didn’t, and I will not,” he said.Rutte also said he had reminded Trump of the sacrifices made by Nato allies in Afghanistan after the US president played down their contribution. “For every two American soldiers who paid the ultimate price, one soldier of an ally or a partner, a Nato ally or a partner country, did not return home,” he said, adding: “I know that America greatly appreciates all the efforts.”