Donald Trump is considering paying people in Greenland as much as $100,000 each to join the United States. The idea has come up as part of his renewed interest in the self governing Danish territory, which he has talked about for years now in public and private conversations.

He has been described as very serious about the idea, pointing to Greenland’s strategic importance for defense and its natural resources. At different times, he has said he was actively discussing buying the territory and even suggested force was not completely off the table.

Because Greenland belongs to Denmark, any attempt to take it would create a major international crisis. Denmark is a NATO member, and an action like this would legally be treated as an attack on Denmark, pushing the alliance into a situation it has never faced before.

More recently, it has emerged that Trump’s administration has discussed sending direct payments to Greenlanders. The amounts being talked about range from $10,000 to $100,000 per person, with the hope that financial incentives could shift public opinion.

According to people familiar with the discussions, the concept of lump sum payments has existed for some time. What has changed is the seriousness of the talks, which have reportedly picked up pace following other recent actions by the administration.

Officials have suggested this approach could explain how Trump might try to effectively buy an island with a population of about 57,000 people. This is despite repeated statements from Greenlandic authorities that the territory is not for sale.

Polling has shown that most people in Greenland oppose any kind of US takeover. Resistance to the idea has been consistent, even as Trump continues to raise the subject and float new ways of making it happen.

Jess Berthelsen, a trade union leader in Greenland, summed up the response clearly when he said: “We are not for sale, and we will not be annexed.” He added that Greenland would decide its own future while continuing to work with Denmark and the United States.

He also addressed the tone of the discussion, saying: “It’s not very comfortable to receive threats from a lifelong friend, a lifelong ally. Cooperation cannot take place if we are receiving threats like these constantly. How can we cooperate when we are receiving constant threats of military intervention?”