Protesters demonstrated in Greenland and Denmark on Saturday against US President Donald Trump’s threats to take over the Arctic island, and demanded that its citizens should be allowed to determine its own future.

Trump has in recent weeks insisted Greenland must come under the control of the United States, saying that “anything less” than that would be “unacceptable.” He argued the US needs the territory for national security purposes, which could in turn strengthen NATO.

His repeated statements have strained diplomatic relations between the US and Denmark, which owns the territory but gives the local population the right to self-determination, while also prompting condemnation from NATO’s European member states.

In Denmark, thousands turned out on Saturday in the cities of Copenhagen, Aarhus, Aalborg and Odense to stand in solidarity with the Greenlandic population.

A protest kicked off later in Greenland’s capital of Nuuk. Just before 2p.m. local time there was an estimated crowd of 5,000 – a large proportion of the island’s population of 56,000. People waved banners including “Yankee go home,” and “Greenland is already great.”

In Copenhagen many waved banners with slogans including “Hands off Greenland” alongside the territory’s red and white flag, according to Reuters. The protests across Denmark were organized by Greenlandic organizations in cooperation with the NGO ActionAid Denmark. A statement from ActionAid said the unrest was planned to coincide with a visit of US senators to Denmark.

“We are demonstrating against American statements and ambitions to annex Greenland,” Camilla Siezing, Chair of the Joint Association Inuit – one of the Greenlandic organizations involved in planning the protests – said.

“We demand respect for the Danish Realm and for Greenland’s right to self-determination. Hopefully, we can show that we are many who support Greenland.”

In Greenland on Saturday, protesters were similarly defiant. Asked what her message to the US president was, one female protester in Nuuk, who didn’t give her name, told CNN, “We are not for sale.”

Another protester named Patricia said, “We have seen what he (Trump) does in Venezuela and Iran. He doesn’t respect anything, he just takes what he thinks is his… He misuses his power.”

A male protester, who didn’t give his name, said, “We do not accept this kind of aggression,” referring to Trump’s threats on Greenland.

“My biggest fear is that the US military come here and try to take over our country. But I don’t think it will happen.”

Amid the escalating situation, a US delegation of bipartisan lawmakers were sent to Copenhagen to meet with leaders from Denmark and Greenland.

In a press conference on Saturday, Democratic Senator Chris Coons, who is leading the delegation, said the Trump administration’s “tempo of statements” around Greenland’s potential acquisition was not constructive.

Senator Coons also expressed his respect to the indigenous people of Greenland, telling journalists that it was a “remote and difficult place to live, and that the population of Greenland has managed to carve out of an exceptionally difficult environment, a culture and an approach to living that is worthy of deep respect.”

The US lawmaker sought to highlight the partnership between the US and Denmark, including in the military sphere, saying that the delegation would visit a cemetery later Saturday to lay a wreath for Danish soldiers who fell fighting alongside American troops in conflicts such as the war in Afghanistan.

Reporting from Greenland’s capital of Nook, CNN’s International Diplomatic Editor Nic Robertson said the visit by the US lawmakers was intended to signal how much Denmark’s military partnership with the US is appreciated. “The visit to that cemetery today to lay a wreath, really for them, will sort of encapsulate how much the United States has valued that partnership, valued the lives laid down by Denmark, by Danish troops,” he said.