LONDON — Nigel Farage warned that Donald Trump’s threats to capture Greenland represent the “biggest fracture” in the transatlantic relationship since the Suez crisis, as he clashed on air with U.S. House Speaker Mike Johnson.

Farage, the leader of Britain’s poll-topping, right-wing populist Reform UK party, has long been seen as a key ally of the U.S. president in the United Kingdom.

But he told Johnson, who appeared on Farage’s GB News show as part of a visit to the U.K., that Trump’s threats to seize control of Greenland and slap tariffs on allies who disagree with him risked shredding relations between the U.S. and fellow NATO members.

“Friends can disagree in private, and that’s fine. That’s part of life, part of politics,” Farage told the senior Republican, who is set to address the British parliament Tuesday. “But to have a U.S. president threatening tariffs unless we agree that he can take over Greenland, by some means, without it seems even getting the consent of the people of Greenland … this is a very hostile act. There’s no other way I can put it.”

Responding, Johnson acknowledged that Trump “has a certain manner in which he goes about doing things,” and accused the U.S. “far-left media” of taking the president “always literally and not seriously.”

“I think what the president has in mind with Greenland is that he understands the strategic significance of it, the increasing significance,” Johnson argued.

Farage said he had heard and agreed with Trump’s concerns about Arctic security, and praised the U.S. president for highlighting that “Europeans haven’t paid enough” toward the continent’s defense.

But he warned “this is the biggest fracture in our relationship since Suez in 1956.” That crisis represented a watershed moment in U.S.-U.K. relations, with President Dwight Eisenhower exerting heavy pressure on the U.K. to withdraw an invading force from Egypt.

“If we don’t get past this,” Farage said of the current rift with the U.S., “it genuinely would be a rupture.”

Farage has long touted a friendship with Trump, and has positioned his Reform UK party as a populist challenger on the right of British politics.

In recent days, however, he has come out against Trump’s vow to levy a 10 percent tariff on allies supportive of Greenland’s autonomy.

“It’s wrong, it’s bad, it would be very, very hurtful to us,” Farage told reporters Monday — as he vowed to try and speak to Trump directly when the pair attend the World Economic Forum at Davos this week.