North Korea 'fires ballistic missile'

North Korea launched a ballistic missile that flew about 500 kilometres, South Korea's military has said.

They said it was North Korea's "show of force" against the Trump administration's hard-line stance on Pyongyang.

"The flight distance was about 500 kilometres, and South Korea and the United States are conducting a close-up analysis on additional information," South Korea's Office of Joint Chiefs of Staff said in a statement.

Japan said that it would make a "strong protest" to the country, through diplomatic routes.

The Trump administration said that it had been expecting a provocation from the tiny Asian country, and said it would weigh all options, in an effort to show resolve but avoid escalation.

It added that it would press China to do more to rein in the country.