North Korea has maintained readiness for nuclear test any time - South Korea

North Korean leader Kim Jong Un provides field guidance at the construction site of Ryomyong Street in this undated picture provided by KCNA in Pyongyang on March 16, 2017. KCNA/via Reuters

SEOUL (Reuters) - North Korea has maintained readiness to conduct a new nuclear test at any time, a South Korean military official said on Friday, amid a report of a possible test within days as Pyongyang defies international pressure.

U.S. and South Korean military surveillance assets were closely monitoring the North's Punggye-ri nuclear test site on the reclusive state's east coast, said the official, who declined to be identified.