North Korea launched a new “tactical nuclear attack submarine” that has been under development for years, with leader Kim Jong Un attending a ceremony at the east coast Sinpho shipyard on Sept. 6, according to state media on Friday.

It will be ready to carry out “both preemptive and retaliatory strikes” and is intended to counter U.S. and South Korean “invasion fleets,” Kim reportedly said in a speech at the event. Experts told NK News it can likely carry nuclear submarine-launched ballistic missiles (SLBMs) and smaller missiles.