North Korea’s state news agency reported that leader Kim Jong Un oversaw a test of long-range surface-to-air missiles at a launch site near the country’s eastern coast.

According to the agency, the test—aimed at evaluating nuclear-armed strategic technologies to develop a new type of high-altitude missile—was successful, destroying aerial targets at a distance of 200 kilometers.

The agency also said that Kim inspected construction work on a nuclear-powered submarine weighing 8,700 tons, capable of launching surface-to-air missiles, without specifying the location or timing of the visit.