The United States has announced that it intends to withdraw from the Open Skies treaty because of violations of the agreement by Russia.
U.S. media reported that President Donald Trump's administration on May 21 notified the other 34 signatories of the accord that it was giving the six months' notice to leave, as required by the treaty.
The 18-year-old treaty, which includes Russia, aims to increase international stability by allowing signatory states to conduct surveillance flights over one another's territories to monitor military installations and other objects.
The White House has accused Russia of violating the treaty, saying Moscow has been blocking the United States from conducting flights over the Baltic Sea city of Kaliningrad and near Georgia, which are permitted by the agreement.
The withdrawal is the latest move by Trump to unilaterally pull the United States from a major global treaty. Last year Washington withdrew from the Intermediate-Range Nuclear Forces Treaty with Russia.
The exit is likely to strain relations with Moscow and upset European allies and some members of Congress.
The concept of allowing Russia and the United States to conduct aerial reconnaissance flights over each other’s territory was first put forward by President Dwight Eisenhower in July 1955. But the Soviet Union balked at the idea.
There was no movement toward a treaty until 1989, when President George Bush breathed new life into it. It still took until January 2002 before the treaty entered into effect.