North Korea fired two short-range ballistic missiles into the sea Wednesday in what appeared to be a statement of defiance as the United States deployed a nuclear-armed submarine to South Korea for the first time in decades.

The launches came as the U.S. and the U.S.-led United Nations Command worked to resolve the highly unusual situation involving a U.S. soldier who crossed into North Korea while on a tour of a border village Tuesday afternoon.

South Korea’s Joint Chiefs of Staff said that from 3:30 to 3:46 a.m. North Korea fired two missiles from an area near the capital Pyongyang that flew about 550 kilometers (341 miles) before landing in waters east of the Korean Peninsula.

The Japanese military said the missiles landed outside of Japan’s exclusive economic zone and no damage to ships or aircraft was reported.

The flight distance of the two missiles roughly matched the distance between Pyongyang and the South Korean port city of Busan, where the USS Kentucky arrived Tuesday afternoon in the first visit by a U.S. nuclear-armed submarine to South Korea since the 1980s.