The US has warned it was ready to defend "ourselves and our allies" after North Korea launched a missile, which landed in Japanese waters for the first time in nearly 20 years.

South Korea said the test-firing of the rocket showed Pyongyang's "ambition to attack neighbouring countries".

It is the fourth reported weapons launch the isolated authoritarian state has carried out in recent weeks, in defiance of the UN Security Council.

Image: Japan's Prime Minister Shinzo Abe condemned the rocket launch as 'an outrageous act'

Seoul said the missile appeared to be a medium-range Rodong missile which flew about 620 miles (1,000km).

Washington has condemned the launch.


Referring to North by its official name, the Democratic People's Republic of Korea (DPRK), US State Department spokeswoman Julia Mason said: "We remain prepared to work with our allies and partners around the world to respond to further DPRK provocations, as well as to defend ourselves and our allies from any attack or provocation."

Japanese defence minister Gen Nakatani said the missile landed in the Sea of Japan some 150 miles (250km) off the country's northern coast.

It was the first time a North Korean rocket had come down in Japan's exclusive economic zone since 1998.

Japan's Prime Minister Shinzo Abe said: "It's a serious threat against our country's security.

"This is an outrageous act that cannot be tolerated."

The launch by the North is an apparent show of force against the planned deployment of a US missile defence system in South Korea.

The latest test also comes amid mounting tensions ahead of a planned US-South Korea joint military exercise later this month.

Last year the drills involved 30,000 American soldiers and 50,000 South Korean troops.

North Korea regularly condemns the exercise as a "declaration of war".

Pyongyang has repeatedly warned of pre-emptive nuclear strikes against the South and US targets.

Relations have been further frayed after Washington decided to personally target the North Korean leader Kim Jong-Un by putting him on a sanctions blacklist over human rights abuses.