MOSCOW, February 14. /TASS/. The United States’ activities in the East are incomprehensible and ungrounded, Russian Defense Minister Sergey Shoigu said on Monday, commenting on the situation with a US submarine near the Kuril Islands.

"The United States’ such activities in the East are absolutely incomprehensible and ungrounded," he said at a meeting with President Vladimir Putin.

A US Virginia-class submarine was spotted by Russia’s anti-submarine forces in the Russian territorial waters near Urup, an uninhabited island in the Kuril Islands chain at 10:40 a.m. Moscow time on February 12. The submarine ignored the orders to the surface and the Russian side used special means, after which the submarine left Russia’s territorial waters at the highest speed.

Following the incident, a note was delivered to the US military attache in Moscow, saying that the Russian defense ministry reserves the right to take all appropriate measures security in Russia’s territorial waters to ensure Russia’s security.