North Korea fires ballistic missile over Japan

North Korea fired an intermediate-range ballistic missile over Japan, prompting Tokyo to activate the country's missile alert system and order people to take shelter.

The last time North Korea fired a missile over Japan was in 2017, at the height of a period of "fire and fury" when Pyongyang's leader Kim Jong Un traded insults with then-US president Donald Trump.

South Korea's military said it had detected the launch of an IRBM, which flew around 4,500 kilometres at an altitude of about 970 kilometres and a speed of around Mach 17.

"Specific details are under close analysis by South Korean and US intelligence," the South's Joint Chiefs of Staff added in a statement.

South Korea's President Yoon Suk-yeol called the launch a "provocation" that violated UN regulations.

Yoon "ordered a stern response and to take corresponding measures in cooperation with the United States and the international community", his office said in a statement.

Tokyo also confirmed the launch of an IRBM, activating the country's missile alert warning system and urging people to take shelter.

"North Korea appears to have launched a missile. Please evacuate into buildings or underground," the government said in an alert issued.

Prime Minister Fumio Kishida said that the launch was "an act of violence following recent repeated launches of ballistic missiles. We strongly condemn this."

Washington condemned the launch.