Protesters flocked to the Danish capital Copenhagen on Saturday to show their support for Greenland, which faces the threat of annexation by U.S. President Donald Trump, and to call for respect for the island's right to self-determination.

Donald Trump asserts that Greenland is vital to the security of the United States due to its strategic location and significant mineral reserves, and has not ruled out the use of force to take control of this autonomous territory of the Kingdom of Denmark.

In front of Copenhagen's City Hall Square, demonstrators chanted "Greenland is not for sale" and waved banners reading "Hands off Greenland," before marching toward the U.S. embassy.

"I am very grateful for the tremendous support we are receiving as Greenlanders (...) We are also sending a message to the world to wake up," said Julie Rademacher, director of Uagut, an association representing Greenlanders in Denmark.

"Greenland and Greenlanders have involuntarily become the front line in the fight for democracy and human rights," she added.

Some protesters also wore baseball caps reminiscent of those worn by Donald Trump supporters, but with the slogan "Make America Great Again" reworked as "Make America Go Away."

Other rallies were also held elsewhere in the country as well as in Nuuk, Greenland's capital, where several hundred protesters led by Prime Minister Jens-Frederik Nielsen marched to the U.S. consulate.

MORE THAN 20,000 PROTESTERS ACCORDING TO ORGANIZERS

Several thousand people filled the streets of the Danish capital, according to Reuters images.

Neither organizers nor police provided official numbers, but according to organizers, more than 20,000 people gathered in Copenhagen—the equivalent of the entire population of Nuuk.

Donald Trump's repeated statements have triggered an unprecedented diplomatic crisis between the United States and Denmark, both founding members of NATO.

An autonomous territory of Denmark since 1979, Greenland has a population of 57,000.

Nearly 17,000 Greenlanders live in Denmark, according to Danish authorities.

All parties in Greenland's political landscape support independence for the island, though they disagree on the timeline for such a transition, and all have recently stated they would prefer to remain within the Kingdom of Denmark rather than join the United States.

Annexation of Greenland is supported by only 17% of Americans, according to an Ipsos poll for Reuters, and both Democrats and Republicans oppose military action.

The U.S. president has cited the security aspect of American control over the territory, arguing it would prevent Russia or China from occupying the island. On Friday, he said he could impose tariffs on countries that do not support his plan.

European soldiers have arrived in Greenland in recent days as part of exercises decided by Denmark and its allies, aimed at reassuring Donald Trump about U.S. security.

(Reporting by Tom Little and Stine Jacobsen in Copenhagen; French version by Zhifan Liu and Gilles Guillaume)