The agreement is written between 34 countries and aims to allow the countries with unmanned aircraft to conduct observation flights over each other's territories.

But now USA is withdrawing, writes AP. And the motivation from the White House is that the flights are too expensive.

Democratic criticism

Several of America's leading Democratic congressmen are very critical of the White House's actions.

They wrote in a letter in April to President Trump that it would undermine alliances with European allies that rely on the treaty to hold Russia accountable for its military activities in the region.

"The administration's efforts to make a major change to our national security policy in the midst of a global health crisis are not only short-term, but also unscrupulous," wrote Congressmen Adam Smith, Eliot Engel, Jack Reed and Bob Menendez.

European concern

Earlier this month, 16 former European military representatives signed a statement supporting the agreement, saying that a US withdrawal treaty would be a blow to global security and undermine various arms agreements.

- The biggest risk, if the US withdraws from the Open Skies Treaty, is that Russia is following suit. The Open Skies Treaty was one of several agreements that promoted security cooperation in Europe, so it would have political consequences if the United States withdrew from it, Ian Anthony at the Peace Research Institute Sipri told SVT in November when the United States announced its plans.

Sweden one of the members

The Open Skies Treaty was signed in 1992 and entered into force in 2002.

The information that comes from the Open Skies flights is valuable. It is possible through voluntary transparency and can form a basis for building trust between the countries, says Ian Anthony.

Sweden is also a member of the Open Skies collaboration.