Reports of hidden N.Korea nuclear efforts raise questions in US

This undated and undisclosed picture released by Korean Central News Agency (KCNA) via KNS shows North Korean leader Kim Jong Un inspecting 1524 Unit of North Korea's People's army. [FIle]

Reports that North Korea intends to secretly maintain some of its nuclear stockpile and production facilities raised questions Sunday about President Donald Trump's insistence that the North was "no longer a nuclear threat," after his historic summit in Singapore.

The Washington Post cited four unnamed US officials who, it said, had seen or been briefed on new intelligence findings that point to preparations for deceiving the United States.