President Donald Trump signed a deal with Denmark and Greenland.

He signed it on Tuesday.

The deal makes Arctic and North Atlantic security stronger.

It also makes things calmer.

Trump often said Greenland should join the U.S.

Now the deal helps with that problem.

He signed it at the U.N. General Assembly in New York.

Trump said the deal was great for Europe.

He said it was great for the United States.

He said it was great for everyone.

He said it was amazing for Greenland.

For months, Trump said he wanted Greenland to join the U.S.

He also said he might take Greenland from Denmark.

Denmark is a NATO ally.

On Tuesday, people asked him about this.

He did not answer.

Officials from the three sides talked for months in secret.

Mette Frederiksen is the Prime Minister of Denmark.

She warned that a U.S. takeover would end the Atlantic alliance.

The deal lets Washington update and grow its work at Pituffik Space Base.

Pituffik is in northwest Greenland.

The U.S. can also make defense areas at Narsarsuaq in the south.

It can make defense areas at Mestersvig in the east.

It may make more defense areas.

It may make its military work or buildings stronger.

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

No non-NATO country may put military buildings in Greenland.

No non-NATO country may keep soldiers there for a long time.

This is true unless the signers agree.

The deal has no end date.

If Greenland becomes independent, it will stay in NATO.

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

Mikkel Runge Olesen is a researcher.

He said Greenland and Denmark can end the crisis.

They do not have to give up sovereignty.

He said the U.S. gets a somewhat better deal.

It is better than the old defense treaty.

But he warned that lost trust will take many years to fix.

Frederiksen called it a deal that can last forever.

Jens-Frederik Nielsen is the prime minister of Greenland.

He called it a win-win-win agreement.