North Korea fires ballistic missile, South's military says

Launch into East Sea occurs days after US aircraft carrier arrives for joint drills

Kim Jong-un, supreme leader of North Korea, may be preparing for the country's seventh nuclear test. AP

North Korea on Sunday fired a ballistic missile into the East Sea, South Korea's military said, just days after a nuclear-powered US aircraft carrier arrived for joint drills.

South Korea's military said the short-range ballistic missile was fired from near the Taechon area of North Pyongyan province just before 7am local time and flew about 600 kilometres at an altitude of 60 kilometres and a speed of Mach 5 before landing in waters off North Korea’s eastern coast.

"North Korea's launch of a ballistic missile is an act of grave provocation that threatens the peace and security of the Korean peninsula and international community," South Korea's Joint Chiefs of Staff said in a statement.

Japan's Defence Minister Yasukazu Hamada said the missile fell outside the country's exclusive economic zone and there were no reports of problems with shipping or air traffic.

The US Indo-Pacific Command said it was aware of the launch and consulting with allies, and reaffirmed Washington's commitment to the defence of South Korea and Japan.

The missile launch comes as US Vice President Kamala Harris is due to visit South Korea after attending former Japanese prime minister Shinzo Abe's funeral on Tuesday.

On Friday, the nuclear-powered USS Ronald Reagan and vessels from its strike group docked in the southern port city of Busan, part of a push by Seoul and Washington to have more US strategic assets in the region.

South Korea's hawkish President Yoon Suk-yeol, who took office in May, has vowed to increase joint military exercises with the US, after years of failed diplomacy with North Korea under his predecessor.

The USS Ronald Reagan will take part in joint drills off South Korea's east coast from Monday until Thursday.

Washington is Seoul's key security ally and stations about 28,500 troops in South Korea to protect it from the North.

The two countries have long carried out joint exercises, which they insist are purely defensive, but North Korea sees them as rehearsals for an invasion.

South Korean and US officials have been warning for months that North Korean leader Kim Jong-un is preparing to conduct another nuclear test.

In May, the North test-fired a short range ballistic missile from Sinpo, a major naval shipyard in North Korea.

The isolated regime has tested nuclear weapons six times since 2006. Its last and most powerful one in 2017, which Pyongyang claimed was a hydrogen bomb, had an estimated yield of 250 kilotonnes.