According to the Foreign Ministry, this was done in the interests of strengthening international security, all the efforts made did not allow to preserve the treaty as it was conceived by its authors.
The Foreign Ministry said the Open Skies treaty fell victim to an internal struggle among various pressure groups in the United States.
In 2020, the U.S. officially notified its partners of its decision to withdraw from the Open Skies Treaty. They explained it by the fact that Russia violated the terms of the treaty by banning observation flights over Moscow, Kaliningrad, South Ossetia, Chechnya and near the borders of Abkhazia. Moscow denied the violations and, in turn, blamed Washington for them.
Source:
Russian Foreign Ministry