DAVOS, Switzerland — President Donald Trump on Wednesday scrapped the tariffs that he threatened to impose on eight European nations to press for U.S. control over Greenland, pulling a dramatic reversal shortly after insisting he wanted to get the island “including right, title and ownership.”

In a post on his social media site, Trump said he had agreed with the head of NATO on a “framework of a future deal” on Arctic security, potentially defusing tension that had far-reaching geopolitical implications.

He said “additional discussions” on Greenland were being held concerning the Golden Dome missile defense program, a multilayered, $175 billion system that for the first time will put U.S. weapons in space.

Trump offered few details, saying they were still being worked out. But one idea NATO members have discussed as part of a compromise with Trump was that Denmark and the alliance would work with the U.S. to build more U.S. military bases on Greenland.

That’s according to a European official familiar with the matter but not authorized to comment publicly. The official, who spoke on condition of anonymity, said it was not immediately clear if that idea was included in the framework Trump announced.

The president has threatened tariffs before only to back away. In April, after first saying he would slap massive import levies on nations from around the world, which prompted a sharp negative market reaction, Trump eased off.

But his change of heart this time came only after he used his speech at the World Economic Forum in the Swiss Alps to focus on Greenland and threatened to upend NATO, an alliance that has been among the globe’s most unshakable since the early days of the Cold War.

In his address, Trump said he was asking for territory that was “cold and poorly located” and that the U.S. had effectively saved Europe during World War II while declaring of NATO: “It’s a very small ask compared to what we have given them for many, many decades.”

“We probably won’t get anything unless I decide to use excessive strength and force, where we would be frankly unstoppable. But I won’t do that, OK?” Trump said.

But Trump has also said repeatedly that, while the U.S. will defend NATO, he wasn’t convinced the alliance will backup Washington, if needed, and suggested that was at least part of the reason for his aggressive stance toward Greenland. That prompted NATO Secretary General Mark Rutte, in a post-speech event with Trump, to say that the alliance would stand with the U.S. if it is attacked.

“You can be assured, absolutely,” Rutte said. A short time later came Trump’s post canceling the tariffs.