The U.S. State Department says Russia has ordered the expulsion of two U.S. military attaches from the U.S. Embassy in Moscow.
The State Department says it disagrees with the move but will comply.
Officials say the incident is not connected to the recent expulsion of two Russian diplomats from Washington.
The Russian Foreign Ministry declined to comment.
U.S.-Russian relations have been strained in recent years due to Washington's accusations of a backslide on human rights under former President Vladimir Putin, who was confirmed as Russia's new prime minister in a Duma vote on May 8.
compiled from wire reports