North Korean leader Kim Jong Un visited a naval unit to oversee the launch of “strategic cruise missiles,” state-run media reported Monday, as the U.S. and South Korea kicked off some of the largest joint military exercises in years.

Kim inspected a flotilla stationed to the Sea of Japan, and watched as the crew of what is believed to be one of the navy’s most advanced warships staged a drill launching the missiles, the official Korean Central News Agency (KCNA) reported without saying when the visit took place.

The report did not say what types of missiles were fired, but images released with the report showed what appeared to be a Hwasal-2 cruise missile, referring to them as “strategic” weapons. Pyongyang often uses the term to suggest that the missiles are capable of carrying nuclear warheads.