Washington DC - President Donald Trump insisted that US control of Greenland was essentially the only option on the table, hours before his vice president, JD Vance, was set to hold crunch talks with Danish and Greenlandic officials.

"The United States needs Greenland for the purpose of National Security. It is vital for the Golden Dome that we are building," Trump wrote on Truth Social.

"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!" he added.

Trump has repeatedly threatened to take over the vast Arctic island – an autonomous territory of Denmark – and he has sounded emboldened since ordering a deadly coup against Venezuela at the start of the month.

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"NATO becomes far more formidable and effective with Greenland in the hands of the UNITED STATES," he wrote Wednesday. "Anything less than that is unacceptable."

The 79-year-old has not ruled out military intervention, alarming its NATO ally Denmark and other European countries. Greenland prime minister, political parties, and citizens have overwhelmingly rejected the prospect of US annexation.

Danish Foreign Minister Lars Lokke Rasmussen and his Greenlandic counterpart were to hold talks later Wednesday in Washington with Vance, as well as US Secretary of State Marco Rubio.

Lokke said he was hoping to "clear up certain misunderstandings."

When asked Tuesday about Greenlandic Prime Minister Jens-Frederik Nielsen's public statement that his country prefers to remain part of Denmark, Trump said: "Well that's their problem."

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"Don't know anything about him, but that's going to be a big problem for him," he told a reporter.

Danish Prime Minister Mette Frederiksen has warned that an attack on a NATO ally would end the alliance, and US lawmakers from both sides of the aisle have moved to block Trump from moving unilaterally.

That didn't stop the Republican from urging the alliance to expel Denmark from Greenland, on the pretext that only the US can protect it from alleged threats posed by China and Russia.

"NATO: Tell Denmark to get them out of here, NOW! Two dogsleds won’t do it! Only the USA can!!!" he posted.