Greenland has said it's not for sale, but that didn't stop top White House economic adviser Larry Kudlow from adding fuel to the idea that the Trump administration wants to purchase the world's largest island from Denmark.

Speaking with "Fox News Sunday," Kudlow, the director of the National Economic Council, said the administration is "looking at" purchasing Greenland.

"It's an interesting story," Kudlow told host Dana Perino. "It's developing. We're looking at it. We don't know."

Kudlow noted that "years ago," then-President Harry Truman sought to purchase the massive island off the Canadian coast.

"Denmark owns Greenland. Denmark is an ally," Kudlow added. "Greenland is a strategic place up there and they've got a lot of valuable minerals. I don't want to predict an outcome. I just know the president, who knows a thing or two about buying real estate, wants to take a look at a potential Greenland purchase."

President Donald Trump's interest in acquiring the 811,000-square-mile island in the North Atlantic was first reported last week by The Wall Street Journal. Citing sources familiar with the deliberations, the Journal reported that Trump has mentioned the idea with "varying degrees of seriousness." NBC News confirmed the president's interest in such an acquisition.

35 PHOTOS Climate change in Greenland See Gallery Climate change in Greenland Airplane Mechanic, David Fuller (L), works with a local worker to move a NASA Gulfstream III during a pre-flight inspection before a flight to support the Oceans Melting Greenland (OMG) research mission, March 12, 2018. REUTERS/Lucas Jackson An iceberg floats in a fjord near the town of Tasiilaq, Greenland, June 24, 2018. REUTERS/Lucas Jackson Pilot in Command Tom Parent inspects the exterior of a NASA Gulfstream III during a pre-flight inspection of the aircraft before a flight to support the Oceans Melting Greenland (OMG) research mission, March 12, 2018. REUTERS/Lucas Jackson Radar Engineer, Ron Muellerschoen, monitors data collection inside a NASA Gulfstream III flying above Greenland to measure loss to the country's ice sheet as part of the Oceans Melting Greenland (OMG) research mission, March 12, 2018. REUTERS/Lucas Jackson An iceberg floats in a fjord near the town of Tasiilaq, Greenland, June 18, 2018. REUTERS/Lucas Jackson Radar Engineer Ron Muellerschoen (L), Radar Engineer Tim Miller (C) and Pilot in Command Tom Parent discuss issues with an autopilot system while flying inside a NASA Gulfstream III above Greenland to measure loss to the country's ice sheet as part of the Oceans Melting Greenland (OMG) research mission, March 13, 2018. REUTERS/Lucas Jackson Airplane Mechanic, David Fuller, inspects a NASA Gulfstream III during a pre-flight inspection before a flight to support the Oceans Melting Greenland (OMG) research mission, March 12, 2018. REUTERS/Lucas Jackson Glacial flow is seen out the window of a NASA Gulfstream III flight to support the Oceans Melting Greenland (OMG) research mission above the east coast of Greenland, March 13, 2018. REUTERS/Lucas Jackson Earth Science Flight Programs Director at NASA, Eric Ianson, looks out at the Greenland ice sheet while inside a NASA Gulfstream III flying above Greenland to measure loss to the country's ice sheet as part of the Oceans Melting Greenland (OMG) research mission, March 13, 2018. REUTERS/Lucas Jackson Safety officer Brian Rougeux uses a drill to install antennas for scientific instruments that will be left on top of the Helheim glacier near Tasiilaq, Greenland, June 19, 2018. REUTERS/Lucas Jackson GPS tracking equipment is left on top of the Helheim glacier near Tasiilaq, Greenland, June 19, 2018. REUTERS/Lucas Jackson Oceanographer David Holland (C) eats with Denise Holland (L), safety officer Brian Rougeux and student Febin Magar (R) in their science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 19, 2018. REUTERS/Lucas Jackson Glacial ice is seen from the window during a NASA flight to support the Oceans Melting Greenland (OMG) research mission above the east coast of Greenland, March 13, 2018. REUTERS/Lucas Jackson An aerial photograph of Oceanographer David Holland's science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Meltwater pools are seen on top of the Helheim glacier near Tasiilaq, Greenland, June 19, 2018. REUTERS/Lucas Jackson Meltwater pools are seen on top of the Helheim glacier near Tasiilaq, Greenland, June 19, 2018. REUTERS/Lucas Jackson A glacial terminus is seen from the window during a NASA flight to support the Oceans Melting Greenland (OMG) research mission above the east coast of Greenland, March 13, 2018. REUTERS/Lucas Jackson Oceanographer David Holland works with student Febin Magar to inspect a seismograph in their science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Safety officer Brian Rougeux carries a piece of a radar dome while working in a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Oceanographer David Holland repairs a broken GPS module at his research camp above the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Student Febin Magar watches as leftover wood burns in a research camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Safety officer Brian Rougeux works to build a semi-permanent structure in a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Student Febin Magar watches as safety officer Brian Rougeux burns leftover wood while working in a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Safety officer Brian Rougeux works with student Febin Magar to assemble a radar dome while working in a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson Safety officer Brian Rougeux works to build a semi-permanent structure in a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 20, 2018. REUTERS/Lucas Jackson A large crevasse forms near the calving front of the Helheim glacier near Tasiilaq, Greenland, June 22, 2018. REUTERS/Lucas Jackson Denise Holland prepares a meal at a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 22, 2018. REUTERS/Lucas Jackson Tabular icebergs float in the Sermilik Fjord after a large calving event at the Helheim glacier near Tasiilaq, Greenland, June 23, 2018. REUTERS/Lucas Jackson Safety officer Brian Rougeux unfastens equipment to inspect it while working in a science camp on the side of the Helheim glacier near Tasiilaq, Greenland, June 22, 2018. REUTERS/Lucas Jackson Sunshine lights up the Helheim glacier near Tasiilaq, Greenland, June 22, 2018. REUTERS/Lucas Jackson Tabular icebergs float in the Sermilik Fjord after a large calving event at the Helheim glacier near Tasiilaq, Greenland, June 23, 2018. This portion between the glacier front and the open ocean is known as the "melange" and is filled with ice, snow and icebergs packed together on their way to a fjord and later the ocean. REUTERS/Lucas Jackson An iceberg floats in a fjord near the town of Tasiilaq, Greenland, June 24, 2018. REUTERS/Lucas Jackson An iceberg floats in a fjord near the town of Tasiilaq, Greenland, June 24, 2018. REUTERS/Lucas Jackson An iceberg floats in a fjord near the town of Tasiilaq, Greenland, June 24, 2018. REUTERS/Lucas Jackson SEARCH "JACKSON GREENLAND" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. An iceberg floats in a fjord near the town of Tasiilaq, Greenland, June 24, 2018. REUTERS/Lucas Jackson SEARCH "JACKSON GREENLAND" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

Trump is scheduled to visit Denmark next month in an unrelated appearance.

The island of roughly 56,000 people is rich in mineral resources and houses an American airbase. At least twice previously, in 1867 and 1946, the U.S. has tried to buy Greenland. Truman offered $100 million but Denmark turned down the offer.

Officials in Greenland strongly indicated there was no opportunity for such a deal to be made. Greenland's Ministry of Foreign Affairs tweeted that the island is "open for business, not for sale."

Kim Kielsen, Greenland's premier, also said in a statement that the island "is not for sale and cannot be sold, but Greenland is open for trade and cooperation with other countries — including the United States.”

Speaking to NBC News, Anna Kûitse Kúko, 63 and a lifelong resident of Greenland, said she believes islanders take the idea "as a sick joke by a crazy president."

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