President Donald Trump signed an agreement with Denmark and Greenland on Tuesday.

The deal aims to strengthen security in the Arctic and North Atlantic.

It also reduces tension over Trump's repeated calls for Greenland to join the United States.

The signing took place during the U.N. General Assembly in New York.

Trump said the deal was very good for Europe, the United States and everyone.

He also said it was incredible for Greenland.

For months, Trump had said he wanted Greenland to become part of the U.S.

He also threatened to take the semiautonomous territory from Denmark, a NATO ally.

On Tuesday, he did not answer questions about whether a U.S. takeover was still possible.

Officials from the three sides negotiated for months in private.

Danish Prime Minister Mette Frederiksen had warned that a U.S. takeover would mean the end of the Atlantic alliance.

The agreement lets Washington modernize and expand its activities at the Pituffik Space Base in northwest Greenland.

The U.S. can also set up defense areas at Narsarsuaq in the south and Mestersvig in the east.

It may establish more defense areas and strengthen its military operations or facilities.

Trump told the U.N. General Assembly that the U.S. would build two very major military bases.

No non-NATO country may set up military bases in Greenland or keep a lasting military presence there.

This is true unless the signatories agree.

The accord has no end date.

If Greenland becomes independent, it will agree to stay in NATO.

It will also take on Denmark's rights and duties under the deal.

Researcher Mikkel Runge Olesen said Greenland and Denmark can end the crisis without giving up sovereignty.

He said the U.S. gets a somewhat better deal than under the existing defense treaty.

But he warned that lost trust will take decades to rebuild.

Frederiksen called it a deal that can last forever.

Greenland's prime minister, Jens-Frederik Nielsen, called it a win-win-win agreement.