North Korea fired at least one ballistic missile early on Friday, according to South Korea’s military. The missile, reportedly a medium-range Rodong-type, flew about 800 km before hitting the sea off the country’s east coast. The launch comes even after the United States and United Nations Security Council imposed stringent sanctions against the isolated country earlier in March, in response to a nuclear test North Korea conducted in January.

South Korea’s Office of the Joint Chiefs of Staff said in a statement that the North may have fired a second missile soon after from the same region, north of the capital city of Pyongyang, Reuters reported. Although it did not confirm the type of missile, the South said 800 km was beyond the range of most short-range projectiles in North Korea’s arsenal. If confirmed, this would be North Korea’s first test of a medium-range missile, capable of reaching Japan, since 2014.

Japan condemned the missile launch, saying it wanted North Korea to “exercise self-restraint”. The US State Department said it was it was monitoring the situation closely and urged to fulfil its international obligations. Just last week, North Korean leader Kim Jong-Un told his country’s military to keep their nuclear warheads on standby and be in “pre-emptive attack” mode. He said it was necessary to keep their arms on standby to prevent attacks from enemy states.