North Korea has fired a surface-to-air missile into the Sea of Japan (East Sea) in its latest show of force. The launch came hours after the US, Japan and South Korea jointly urged Pyongyang to scale down its provocative acts.

South Korea's Joint Chiefs of Staff (JCS) confirmed it was a surface-air-missile, which was launched at about 1pm local time. It added the anti-aircraft missile was launched from South Hamgyong Province in North Korea. It was earlier thought to be a ballistic missile but South Korean authorities clarified it was a surface-to-air projectile after examining the trajectory.

South Korean forces have been kept on high alert following the launch. The projectile flew at least 100kms, according to the JCS.

Earlier, Seoul's Yonhap news agency cited an unnamed South Korean military official as saying that the projectile was thought to be a ballistic missile.

Tensions have remained high on the Korean peninsula in the past several months following the North's fourth nuclear test in January and long-range rocket launch in February.

The North's latest defiant act has come within hours of the condemnation issued by Seoul, Tokyo and Washington of its nuclear activities. Pyongyang has launched several projectiles in the past week as a show of belligerence against its adversaries.