Moscow: A Russian anti-submarine destroyer chased off a US submarine near the Kuril Islands, forcing it to leave the country's territorial waters, Moscow said Saturday, amid rising tensions over Ukraine.
The US military however denied the account.
Russia's defence ministry said that during planned military drills the Marshal Shaposhnikov destroyer had detected a US Navy Virginia-class submarine in Russian territorial waters near the Kuril Islands in the northern Pacific.
When the submarine ignored demands to surface, the crew of the frigate "used appropriate means" and the US submarine left at full speed, the ministry said, without providing further details.
The ministry said it had summoned the US defence attache in Moscow over the incident.
"In connection with the violation by the US Navy submarine of the state border of the Russian Federation, the defence attache at the US embassy in Moscow was summoned to the Russian defence ministry", the defence ministry said.
The statement from the US military, however, said: "There is no truth to the Russian claims of our operations in their territorial waters."
Captain Kyle Raines, spokesman for the US Indo-Pacific Command, said he would not comment on the precise locations of US submarines.
But he added: "We do fly, sail, and operate safely in international waters."
The alleged incident took place near the Kuril island of Urup, which is controlled by Russia.
It comes amid rising tensions between Russia and the West that have seen Moscow surround Ukraine on three sides with more than 100,000 troops.
Washington has warned that an all-out invasion could begin "any day".
Russian leader Vladimir Putin on Saturday condemned such claims as a "provocation".