North Korea fires ballistic missile over Japan

North Korea has launched an "unidentified missile" over Japan in its latest highly provocative bomb test, according to reports.

Japan's NHK broadcaster said the projectile appeared to have been fired over the north of the country before landing in the ocean.

Warning sirens were sounded in Japan's northern island of Hokkaido as the missile was launched. Community loudspeakers instructed people to get inside any building and go to the basement.

TV stations relayed the warnings and residents in several prefectures got the emergency message on their mobile phones. Trains and subways on Hokkaido briefly stopped for safety checks.

The missile entered the country's airspace at around 7.16am local time, and landed in waters some 2,000 miles off the coast, NHK reported.

It said there was no attempt to intercept the missile in mid-air, according to Japan's government.

Japanese Prime Minister Shinzo Abe and US Defence Secretary Jim Mattis both called the launch a reckless act.

Foreign Secretary Boris Johnson condemned the test as "illegal" and the latest sign of "provocation" from Pyongyang.

"Yet another illegal missile launch by North Korea. UK and international community will stand together in the face of these provocations."

In a later statement, he said the UK "stand firmly by Japan and our other international partners".

He said: "This week the most stringent UN sanctions regime placed on any nation in the 21st century was imposed on North Korea, after being unanimously agreed at the UN Security Council.

"These measures now need to be robustly enforced. We urge all states to play their part in changing the course North Korea is taking."

China's foreign ministry also condemned the launch and called for all sides to seek dialogue to reduce tensions.

Spokeswoman Hua Chunying told reporters the situation remains "complex, sensitive and severe."

Russia "resolutely" condemned the launch with a spokesman for President Putin warning the tests would "lead to the further growth of tensions and the further escalation of tensions on the (Korean) peninsula."

The French Foreign Ministry says the UN Security Council is holding an emergency meeting to discuss the latest missile launch.

A previous North Korean missile launch. Credit: AP

South Korea's Yonhap said the missile appeared to have been fired from near North Korea's capital of Pyongyang.

It was not immediately clear what type of bomb had been fired, with South Korean military officials saying they were still gathering further information.

The country's President Moon Jae-in will preside over a National Security Council session on Friday to the latest launch by the North, Yonhap said.

South Korea's president Moon Jae-in talked over the phone with Abe about the two countries' response.

The latest launch comes amid growing tensions on the Korean peninsula over the North's developing nuclear missile programme.

North Korean leader Kim Jong-Un examines a missile. Credit: AP

North Korea recently conducted its sixth nuclear test launch with what is said was a hydrogen bomb that could be more destructive than an atomic weapon.

Experts believe that its nuclear weapons programme is developing quickly, with warning that it could soon be in possession of missiles which could reach Europe.

US President Donald Trump has repeatedly warned Pyongyang that he is ready to use both diplomatic pressure and force to check the one-party state's nuclear ambitions.

Earlier this week, the United Nations brought in a fresh round of tough economic sanctions against the already bitterly impoverished and isolated state.

However, it's leader Kim Jong-Un has remained defiant, insisting that the country will continue to develop its nuclear weapons.