North Korea fires unidentified ballistic missile towards the East Sea," Seoul's Joint Chiefs of Staff says. (Photo/AP Archive)

North Korea has fired at least one ballistic missile, Seoul's military said, as the United States and South Korea warned any nuclear attack would lead to the end of Pyongyang's regime.

"North Korea fires unidentified ballistic missile towards the East Sea," Seoul's Joint Chiefs of Staff said on Sunday, referring to the body of water also known as the Sea of Japan.

The launch came after warnings from officials in Seoul and Tokyo that nuclear-armed North Korea was preparing to test-fire a missile, including one of its longest-range an intercontinental ballistic missiles (ICBM) this month.

The test comes as Seoul and Washington warned Pyongyang that any nuclear attack on the United States and South Korea would result in the end of the North Korean regime.

The two allies held their second session of the Nuclear Consultative Group in Washington on Friday, where they discussed nuclear deterrence in the event of conflict with the North.

Tensions in the Peninsula

The launch also comes as Pyongyang marks the anniversary of the death of leader Kim Jong-un's father and predecessor Kim Jong-il who died on December 17, 2011.

North Korea last year declared itself an "irreversible" nuclear power and has repeatedly said it will never give up its nuclear programme, which the regime views as essential for its survival.

Tensions on the Korean Peninsula are at their highest point in years, with the both the pace of North Korean weapons demonstrations and South Korea’s combined military exercises with Japan intensifying in a cycle of tit-for-tat.

And last month Pyongyang successfully put a military spy satellite into orbit. It has since claimed its eye in the sky was already providing images of major US and South Korean military sites.