SEOUL (XINHUA) - South Korea's defence chief said Wednesday (July 5) that there has been no specific sign of another nuclear test by North Korea.

Defence Minister Han Min Koo told lawmakers that though North Korea can conduct another nuclear test at any time, no specific sign was detected for such test.

Speculation emerged that North Korea may carry out its sixth nuclear detonation in the near future following its claim on Tuesday (July 4) that it successfully tested a new type of intercontinental ballistic missile (ICBM), called Hwasong-14.

In the past, North Korea tended to test launch a long-range ballistic rocket in parallel with a nuclear detonation with a certain time gap.

Pyongyang carried out its fourth and fifth atomic bomb tests in January and September last year (2016), escalating tensions on the Korean Peninsula.

North Korea's capability of miniaturising a nuclear warhead, the defence chief said, was estimated to have reached a significant level.In response to the North's test-launch of an ICBM, the missile units of South Korea and the United States conducted joint ballistic missile exercises along the east coast of South Korea.

Mr Han said it was the first time that the two allies carried out joint missile drills in response to North Korea's provocation.

Touching on the Tuesday test, the minister said that whether North Korea obtained a re-entry technology of ICBM has not been confirmed though the missile was estimated to have a range of 7,000-8,000km.

The missile flew about 930km and was lofted as high as around 2,800km. The Pentagon confirmed it was a new ICBM.