Danish Member of the European Parliament, Anders Vistisen told U.S. President Donald Trump to “f**ck off” during a speech opposing Trump’s plan to annex Greenland.

During European Parliament on Tuesday, Vistisen said:

Let me put this in words you might understand: Mr. President...f*** off.

Vistisen was interrupted by the chair who said his language was not Parliamentary, and “was against the rules,” according to European outlets.

The attack came after a Trump ally told United Kingdom Parliamentary Members that he was visiting London to “calm the waters” in the Greenland dispute.

On Saturday, in response to European allies coming to Greenland’s defense and increasing military presence on the island, Trump threatened to impose 10% tariffs on Denmark, Norway, Sweden, France, the United Kingdom, the Netherlands and Finland — all U.S. allies — starting on Feb. 1. And if no deal is reached to give the U.S. control of Greenland, then tariffs could rise to 25%, according to Trump.

Trump’s threats of tariffs over Greenland were called “a mistake especially between long-standing allies,” by top EU official Ursula Von Der Leyen.

While speaking at the World Economic Forum in Davos, Switzerland, which Trump is expected to attend, Von Der Leyen called into question the U.S. President’s trustworthiness after he agreed last year not to impose more tariffs on EU countries.

The European Union and the United States have agreed to a trade deal last July,” Von der Leyen said. “And in politics as in business – a deal is a deal. And when friends shake hands, it must mean something.” Adding that the EU’s response “will be unflinching, united and proportional.

Trump has repeatedly stated that the U.S. needs to control Greenland for national security reasons — deterring potential threats from China and Russia. He has repeatedly asserted that Greenland and European allies cannot protect the island.

The United States needs Greenland for the purpose of National Security," Trump said in a social media post earlier this month. "It is vital for the Golden Dome that we are building. NATO should be leading the way for us to get it. IF WE DON’T, RUSSIA OR CHINA WILL, AND THAT IS NOT GOING TO HAPPEN!

Trump is expected to speak at the World Economic Forum on Wednesday and said in a social media post that he has agreed to “a meeting of various parties” there.