A Russian naval vessel chased away a US submarine in Russian waters in the Pacific after the submarine ignored the ship's orders for it to surface, Interfax news agency cited the defence ministry as saying on Saturday.
Russia accused Washington of breaking international law and creating a national security threat over the incident, which came at a time of high tensions between Moscow and Washington over a Russian military buildup near Ukraine.
There was no immediate comment from the United States.
The crew of the Marshal Shaposhnikov frigate used "corresponding means" to make the submarine leave Russian waters, the defence ministry was quoted as saying.
It said it had called in the US defence attache over the incident.
The submarine was spotted near the Kuril islands early on Saturday as Russia was conducting naval exercises with its Pacific Fleet and it was ordered to surface immediately, the Russian ministry was quoted as saying.
It said the order was ignored by the US submarine's crew, leading the Russian frigate to take unspecified action to make it leave.
"The US submarine ... left Russian territorial waters at maximum speed," the defence ministry was quoted as saying.
Russia's defence minister spoke by phone with his US counterpart on Saturday as the United States and other Western nations warned that war in Ukraine could ignite at any moment.
US President Joe Biden and Russia's Vladimir Putin spoke for an hour by phone later in the day.