Ole Diehl, deputy director at Germany’s foreign intelligence agency BND, apparently told lawmakers in a private meeting that he was “certain” about Kim Jong Un’s military capability.
But Mr Diehl also insisted the agency saw talks between North and South Korea as a positive sign, according to German newspaper Bild am Sonntag, citing sources.
The BND has not commented on the report.
A senior North Korean diplomat left for Finland on Sunday for talks with former US and South Korean officials, South Korean media reported.
It comes ahead of a possible US-North Korean summit after President Donald Trump agreed to meet Kim Jong Un to discuss North Korea’s nuclear disarmament.
However intelligence analysts warned this week that North Korea has started testing a nuclear reactor that could be used to produce weapons-grade plutonium.
Kim Jong Un is pursuing nuclear and missile programmes in defiance of UN Security Council sanctions and the North has made no secret of its plans to develop a missile capable of hitting the US mainland.
The regime defends the programmes as a deterrent against perceived plans for invasion by the United States, which has 28,500 troops in South Korea.