North Korea has released the first images of its under-construction nuclear-powered submarine, which is likely being built with assistance from Russia. The nuclear-powered submarine can pose a major threat to Pyongyang’s immediate neighbor,

The fresh deployment comes after North Korea suffered heavy casualties on the front lines in Russia’s war against Ukraine, the South’s spy agency says.

North Korea fired several ballistic missiles into the sea on Monday, South Korea’s military said, hours after South Korean and U.S. troops kicked off their large annual combined drills, which the North views as an invasion rehearsal.