N.Korea: 'very dangerous challenge' if Trump calls Kim 'Rocket Man' again

Should U.S. President Donald Trump call North Korean leader Kim Jong Un "Rocket Man" again, that would represent a "very dangerous challenge" reminiscent of two years ago, a senior North Korean official warned on Thursday.

Choe Son Hui, who was quoted by state-run KCNA news agency, was referring to a time when tensions between when Washington and Pyongyang ran high.

Trump said on Tuesday he still had confidence in the North Korean leader but noted that Kim "likes sending rockets up".

"...That's why I call him Rocket Man," Trump told reporters at a NATO meeting in London.