In a lengthy post to social media on Saturday, President Trump said the US would implement 10% tariffs on eight European countries he says are getting in the way of a US purchase of Greenland.

The tariffs would begin Feb. 1 and apply to “any and all goods sent to” the US. The levies on Denmark, Norway, Sweden, France, Germany, the UK, the Netherlands, and Finland would be raised to 25% on June 1 if no agreement is in place.

“China and Russia want Greenland, and there is not a thing that Denmark can do about it. They currently have two dogsleds as protection, one added recently,” Trump wrote. “Only the United States of America, under PRESIDENT DONALD J. TRUMP, can play in this game, and very successfully, at that!”

Protesters rallied against Trump’s plans in Denmark and Greenland on Saturday. In Greenland’s capital city of Nuuk, thousands chanted “Kalaallit Nunaat” — the ‍island’s name in Greenlandic — as they marched to the U.S. embassy.

Those protests came after former NATO head and former Danish prime minister Anders Fogh Rasmussen said Trump was speaking like a “gangster” and using Greenland as a “weapon of mass distraction” from the war in Ukraine.

Meanwhile, the US Supreme Court’s first two opportunities to issue a verdict this year on the implications and legality of Trump’s global duties on trade partners have come and gone without a decision.

Whatever the ruling, the case is being closely watched, as companies like Costco (COST) bring lawsuits against the US government in the hope of securing a refund on import duties if the court rejects Trump’s authority to impose tariffs.

The court heard arguments in early November. Both conservative- and liberal-leaning justices asked skeptical questions of the method by which the president imposed his most sweeping duties. Trump imposed his tariffs by invoking a 1977 law meant for national emergencies.

The Trump administration also made appeals to the court last year, and in recent weeks, Trump has frequently expressed concern over the ruling, saying losing the ability to tariff other countries would be a “terrible blow” to the US. On Monday, he went even further.

“If the Supreme Court rules against the United States of America on this National Security bonanza, WE’RE SCREWED!” he wrote on social media.

Canadian Prime Minister Mark Carney and China’s President Xi Jinping have reached a deal to cut tariffs on Chinese electric vehicles, in return for lower duties on Canadian farm products.

The US and Taiwan reached a trade deal Thursday, the countries announced. The US said the deal would “drive a massive reshoring of America’s semiconductor sector.”