North Korea fires missile into Japan waters for first time

North Korea Wednesday fired a ballistic missile directly into Japanese-controlled waters for the first time, drawing an outraged response from Tokyo and ramping up tensions with the United States and South Korea.

The US military said the North had actually launched two Rodong intermediate-range missiles simultaneously, but one appeared to have exploded on take-off.

The launches followed a North Korean threat of "physical action" over the planned deployment of a sophisticated US anti-missile system in South Korea, and came just weeks before the start of large-scale joint South Korea-US military exercises.

Japan said the one missile had landed in the Sea of Japan (East Sea), some 250 kilometres (155 miles) off its north coast and within its Exclusive Economic Zone (EEZ).

"It's a serious threat against our country's security," Prime Minister Shinzo Abe told reporters. "This is an outrageous act that cannot be tolerated."

The United States condemned what it called a clear violation of UN Security Council resolutions explicitly banning North Korea's use of ballistic missile technology.

"This provocation only serves to increase the international community’s resolve to counter (North Korea's) prohibited activities," said Pentagon spokesman Gary Ross.

It was the first time a North Korean missile has been fired direct into Japanese waters. The second stage of a missile fired over Japan had splashed down inside the EEZ off Japan's Pacific Ocean coast in 1998.

Japan's top government spokesman Yoshihide Suga slammed Pyongyang for providing no advance warning of Wednesday's test.

Pyongyang has conducted a series of missile tests this year in defiance of UN sanctions imposed after its fourth nuclear test in January.

On July 19 it launched three ballistic missiles in an exercise that the North said simulated a nuclear strike on the South.

That came just days after Washington and Seoul announced an agreement to deploy the US Terminal High Altitude Area Defence, or THAAD, system in South Korea by the end of next year -- a move condemned by Pyongyang and also vehemently opposed by China and Russia.

South Korean Foreign Minister Yun Byung-Se said Wednesday's missile test only served to "underline the need to deploy THAAD".