Danish state could face legal action over deal that gives US powers on its soil

Denmark could face legal action over an agreement that gives the US sweeping powers on Danish soil, over claims it is “unconstitutional” and could pose problems in talks with Washington over Greenland.

The agreement, which was signed under the Biden administration in 2023 and was passed by the Danish parliament last year, gives the US “unhindered access” to its airbases and powers over its civilians.

Since then, Donald Trump has made threats to invade Greenland, part of the kingdom of Denmark, resulting in a diplomatic crisis between the longtime allies and a deployment of soldiers to Greenland by a number of European countries.

Theresa Scavenius, an independent MP, plans to sue the Danish state over the agreement on the basis that she believes it to be unconstitutional. The Danish constitution states that its sovereignty can be transferred to “international authorities” but only with a constitutional amendment that requires the support of five-sixths of parliament, which the defence agreement does not have.

“The law is unconstitutional because it delegates authority to the US governmental bodies or soldiers on Danish territory over Danish civilians. That is explicitly not allowed in our constitution,” Scavenius told the Guardian.

While the agreement does not apply to Greenland, critics claim the Trump administration’s statements on Greenland show the US could be willing to use force on civilians.

It was essential that any constitutional matters be resolved urgently before beginning negotiations over Greenland, said Scavenius.

Despite strong criticism from politicians and human rights experts – and heightened tensions between the US and Denmark after Trump’s previous push to acquire Greenland – MPs voted overwhelmingly in favour of the defence agreement in June 2025.

The agreement keeps US soldiers in Denmark under US jurisdiction, gives them access to Danish airbases in the Danish cities of Karup, Skrydstrup and Aalborg, and grants American soldiers and military police powers over Danish civilians at these locations and outside them.

At the time, the government said it did not have the potential to surrender Danish sovereignty and was not a violation of the Danish constitution. The prime minister, Mette Frederiksen, said tensions between Denmark and the US made it even more necessary to maintain close ties. “The problem is not too much involvement from the US in Europe,” she said at the time. “On the contrary, the risk is that the US will withdraw and move troops away or stop donations to Ukraine.”

Scavenius has submitted a request for free legal aid, a process that is expected to take several weeks, after which she plans to sue the Danish state.

The Danish Institute for Human Rights has said the agreement risks giving US soldiers the right to stop demonstrations outside their bases and would prevent Denmark from prosecuting them if they used excessive force.

Peter Vedel Kessing, a senior researcher at the Danish Institute for Human Rights, told the Guardian in May: “If the bill is passed and American soldiers carry out illegal acts in Denmark, it will be beyond Danish control and outside the reach of the Danish legal system to prosecute such actions.”

The Danish defence ministry said it had noted that a claim was expected to be filed but declined to comment further. A spokesperson said: “As the ministry has not received such a claim at this time, the ministry has no comment.”