Trump advisor Kevin Hassett calls for "cooler heads to prevail" as president threatens Denmark with tariffs over Greenland acquisition deal negotiations.

National Economic Council Director Kevin Hassett urged "cooler heads to prevail" Sunday as European leaders blasted President Donald Trump’s tariff threats aimed at forcing a Greenland purchase deal.

"When you are engaged in negotiation with any country and with President Trump, you'll see both sides take very strong extreme positions, but, in the end, the president is the person who wrote ‘The Art of the Deal’ because he's so good at deal-making," Hassett told Fox News' Jacqui Heinrich.

"I think right now it's really a good time for cooler heads to prevail and for us to disregard the rhetoric and get to the table and see if there can't be a deal that's worked out that's best for everybody," he added.

Hassett’s remarks come as Trump seeks to bring Denmark to the negotiating table over Greenland, an autonomous Arctic territory, by threatening 10% tariffs on Danish and other European goods, a move that has sparked sharp backlash from European leaders.

TRUMP KNOWS GOOD REAL ESTATE — AND HE KNOWS GREENLAND'S VALUE TO NATIONAL SECURITY

"Any decision about the future status of Greenland belongs to the people of Greenland and the Kingdom of Denmark alone," British Prime Minister Keir Starmer said Monday.

"The use of tariffs on allies is completely wrong," he added.

Trump's tariffs would affect the United Kingdom, along with Denmark, Norway, Sweden, France, Germany, the Netherlands and Finland.

TRUMP'S GREENLAND TAKEOVER WOULD LIKELY ENTAIL ENORMOUS PRICE TAG: REPORT

If no deal is reached, Trump said the 10% tariffs would increase to 25% on June 1. 

The European Union is reportedly considering the use of its trade "bazooka" — retaliatory tariffs — against the U.S. in response to the proposed duties.

Despite the possible escalation, Hudson Institute senior fellow Rebeccah Heinrichs sees room for an off-ramp.

"The president's right that Greenland is very important. If you look at a Russian missile path [toward the U.S.], the shortest path flies over Greenland… so that is a really important strategic area for the United States, but it is [also] for NATO, and the president can collaborate," she told Fox News on Monday. 

"The Danes are very willing to work with President Trump under the current treaty we have with them, so it's good for the United States to work with our allies on this point."

Danish Prime Minister Mette Frederiksen has insisted that "Europe won't be blackmailed" by Trump, however.

She issued a joint statement along with other EU leaders on Sunday, suggesting the tariffs risked "undermin[ing] transatlantic relations and risk a dangerous downward spiral," the BBC reported.

Fox News' Michael Dorgan contributed to this report.