North Korea on Sunday confirmed that it had test fired an Hwasong-15 intercontinental ballistic missile (ICBM) in a 'sudden launching drill' to confirm the weapon's reliability.
According to state media, the ICBM, that was tested on Saturday, flew over 900 km and landed in Sea of Japan.
Pyongyang said that the test showed it was capable of countering hostile forces like the US and South Korea.
Authorities have threatened to unleash an "unprecedentedly strong" retaliation to any such drills-which it insists are being done in preparation to invade North Korea.
In a statement on Sunday, Kim Yo Jong, sister of Kim Jong said that any hostile acts would be met with a "strong and overwhelming" response.
She also urged the US to end what she called "threats" against the regime.
She also added that South Korean capital, Seoul would not be targeted by North Korean missiles, reported BBC.
Hwasong-15 was first tested in 2017. The launch, guided by the Missile General Bureau, was conducted on an "emergency firepower combat standby order" given at dawn, followed by a written order by Kim Jong Un, the KCNA said.
Under the United Nations Security Council resolutions, North Korea's ballistic missile and nuclear weapons programmes are banned, but Pyongyang says its weapons development is necessary to counter "hostile policies" by Washington and its allies.
Earlier on Friday, North Korea showed off its massive military might in a parade on Friday that included more than dozen ICBMs.
Japanase Prime Minister Fumio Kishida said that the missile launched has splashed sown west of Hokkaido, in Japan's exclusive economic zone at 18:27 (09:27 GMT).
In the earlier tests conducted last year, an ICBM had reached an altitude of 6,100 km.