South Korea's military said Saturday that North Korea fired at least one "unspecified projectile," which could be Pyongyang's ninth missile test since the beginning of the year.
The South Korean Joint Chiefs of Staff said in a statement that North Korea fired an unspecified projectile toward the sea east of the Korean Peninsula.
On Monday, North Korea announced that it had conducted a "critical" test to develop a satellite for reconnaissance purposes.
Japanese Defense Minister Nobuo Kiichi said it was estimated that the projectile fired by North Korea had a height of 550 km and a distance of 300 km.
He added that it appears that the projectile fell outside Japan's exclusive economic zone, but Tokyo will continue to monitor the situation and work closely with the United States to collect and analyze information.
North Korea is prohibited from firing ballistic missiles under UN Security Council sanctions against Pyongyang over its weapons programmes, though it conducted a record number of weapons tests last January before suspending its tests during the Winter Olympics in Beijing.
The development of a military reconnaissance satellite with hypersonic weapons tested a short time ago is one of the main goals announced by North Korean leader Kim Jong Un last year in the field of defense.
Analysts say that the development of a reconnaissance satellite provides North Korea a cover for testing ICBMs, which are banned, because long-range missiles use the same technology.
Analysts expected that Pyongyang would benefit from the United States' preoccupation with the Russian war on Ukraine to conduct new tests.
North Korea's new experiences come at a sensitive time in the region, as South Korea prepares to elect its president on the ninth of this March.