US Vice-President JD Vance said that he's joining his wife on a trip to Greenland, starting Friday, suggesting in an online video that global security is at stake.

"Speaking for President Trump, we want to reinvigorate the security of the people of Greenland because we think it's important to protecting the security of the entire world," said Vance, adding that leaders in Denmark and North America had "ignored" Greenland for "far too long".

The office of US Second Lady Usha Vance said on Sunday that she would depart Thursday for Greenland and return on Saturday. Usha Vance and one of the couple's three children had planned to visit historic sites and learn about Greenland's culture. The vice-president said he didn't want to let his wife "have all that fun by herself" and said he plans to visit a Space Force outpost in the northwest coast of Greenland.

However, ahead of the vice-president's announcement that he would join his wife, discontent from the governments of Greenland and Denmark had been growing sharper, with the Greenland government posting on Facebook on Monday night that it had "not extended any invitations for any visits, neither private nor official".

Meanwhile, plans for National Security Advisor Mike Waltz and Energy Secretary Chris Wright to also travel to Denmark are further inflaming tensions between Washington and Copenhagen and Nuuk, Greenland's capital.

Officials in Denmark and Greenland have denounced the visits. Greenland Prime Minister Múte Bourup Egede called Waltz's visit in particular "highly aggressive". Danish Prime Minister Mette Frederiksen called the US delegation's visit "unacceptable pressure".

Jens-Frederik Nielsen, leader of Greenland's Demokraatit party and poised to be the island's next leader following elections earlier this month, said the visit showed a "lack of respect for the Greenlandic people".

During his first term, Donald Trump floated the idea of purchasing the world's largest island, even as Denmark, a NATO ally, insisted it wasn't for sale. The people of Greenland have also firmly rejected Trump's plans.

Although Vance's decision to visit a US military base in Greenland has removed the risk of violating potential diplomatic taboos by sending a delegation to another country without an official invite, the way such an uninvited visit is going to unfold for its ulterior purpose is a worrying sign that the Trump administration is trying to break the envelope to push through its territorial grab plan.

The biggest threat to Greenland is not any other country but the one that claims it will protect its security.