Roughly two weeks before U.S. President Donald Trump heads to the Danish capital for his first state visit there, he has reportedly expressed interest in buying Greenland, the north Atlantic island that forms a key part of the Kingdom of Denmark.

The report has caused some bemusement in Danish political circles, with a former prime minister asking whether it was a joke. But according to the Wall Street Journal, which cites people familiar with the deliberations, Trump has repeatedly expressed interest in striking a deal to purchase the island, and even asked his White House counsel to explore the idea.

Lars Lokke Rasmussen, who was prime minister until June and now heads the opposition in Denmark, tweeted that Trump’s idea “must be an April Fool’s Day joke,” albeit out of season. But in the U.S., the idea is being taken seriously in some corners. Republican Representative Mike Gallagher tweeted that the suggestion isn’t “crazy,” adding that the U.S. “has a compelling strategic interest in Greenland, and this should absolutely be on the table.” Democrats appeared less enthusiastic, with Representative Steve Cohen tweeting that the idea was one for the “cryonic memorial.”

The Wall Street Journal report comes as Trump prepares to make his first formal visit to Denmark, where he will meet with Prime Minister Mette Frederiksen and attend a state dinner hosted by Queen Margrethe II on Sept. 2-3. The meeting will focus, among other things, on Greenland, where the U.S. has built several military bases and weather stations since WWII. In 1968, a B-52 bomber carrying nuclear weapons crashed near the Thule air base in northwestern Greenland, causing radioactive contamination.

Frederiksen, who became prime minister after her Social Democratic party won elections in June, will make her first official visit to Greenland next week during which she’ll conduct formal talks with the island’s premier, Kim Kielsen. Greenland has home rule, but defense and foreign affairs remain under Danish governance. The island has representation in Washington D.C. and in the European Union.

More than 80 per cent of Greenland’s 2.2 million square kilometers (830,000 square miles) are covered in ice, and the island has attracted considerable attention recently amid concerns that climate change is causing that ice to melt at a record pace. Greenland’s population of just 56,000 is concentrated around its coast lines.

The Wall Street Journal noted that it’s unclear how Trump would go about acquiring the Danish territory and said that neither the White House nor the State Department responded to a request for comment.