Greenland thanked European nations on Sunday for maintaining their support for the Arctic island despite being targeted by punitive tariffs from US President Donald Trump, who wants to annex the Danish-ruled territory.

France, Germany, Britain and other European countries this week sent small groups of military personnel to Greenland at Denmark’s request, prompting Trump to threaten trade tariffs on eight European allies until the US is allowed to buy the island.

European leaders on Saturday warned of a “dangerous downward spiral” over Trump’s tariff threat, vowing to uphold their backing for Greenland and Denmark’s sovereignty. Ambassadors from the European Union’s 27 countries will convene on Sunday to discuss their response to the tariff threat.

“We live in extraordinary times that call not only on decency but also great courage,” Greenland cabinet minister Naaja Nathanielsen, responsible for the island’s business, energy and minerals, said in a statement.

Trump says Greenland is vital to US security because of its strategic location and mineral deposits, and has not ruled out using force to take it, raising alarm in Europe at the prospect of confrontation between NATO states.

Greenland’s own companies were unlikely to see a significant impact from the US tariffs, said Christian Keldsen, the head of the Greenland Business Association.

“The goal, therefore, does not seem to be Greenland, but to put pressure on our allied European NATO countries,” Keldsen wrote on LinkedIn, thanking governments for standing firm.

Thousands of protesters in Denmark and Greenland demonstrated on Saturday and called for Trump to leave the Arctic island to determine its own future.

Denmark’s foreign minister said he will visit Oslo on Sunday, followed by London and Stockholm in the coming days to discuss the need for NATO countries to boost their coordination, presence and deterrence in the Arctic.

“What our countries have in common is that we all agree that NATO’s role in the Arctic must be strengthened, and I look forward to discussing how,” Foreign Minister Lars Lokke Rasmussen said in a statement.

Sweden on Saturday began intensive discussions with other EU countries as well as Britain and Norway to work out a coordinated response, Prime Minister Ulf Kristersson said.

“We will not let ourselves be blackmailed,” Kristersson said.

Finland’s president said the Danish-led effort to reinforce Greenland’s defence was an important part of boosting the overall security in the Arctic, and that allies must resolve their differences through discussion, not pressure.

“Dialogue with the United States continues. Tariffs would undermine the transatlantic relationship and risk a dangerous downward spiral,” President Alexander Stubb said in a statement.

Norway’s prime minister said there was broad agreement in NATO to strengthen security in the Arctic.

“Threats have no place among allies. Norway’s position is firm: Greenland is part of the Kingdom of Denmark,” Prime Minister Jonas Gahr Stoere said in a statement.