North Korea's Kim Jong-un expresses 'bitter sorrow' over bus crash that killed 32 Chinese

North Korean leader Kim Jong-un visited Chinese embassy in Pyongyang to express his sorrow to the bus crash incident occurred on Sunday, state media reported on Tuesday.

North's central news agency KCNA quoted Kim saying that "the unexpected accident brought bitter sorrow to his heart and that he couldn't control his grief at the thought of the bereaved families who lost their blood relatives".

On Sunday a bus plunged from a bridge in North Hwanghae province in North Korea leaving thirty-two Chinese tourists and four North Koreans dead.

Kim Jong-un also met Chinese ambassador Li Jinjun and later he visited crash survivors in hospital.

China is North Korea's most important economic, diplomatic and sole ally but the relations between both countries has been sored through time due to Pyongyang's numerous missile and nuclear tests.

Kim visiting crash survivors in hospital and expressing his sorrow is being observed by experts as an indication of how much seriousness North Korea is taking the accident.

News reports also cited Kim saying that his government would take follow-up measures to the accident with "utmost sincerity".

Kim Jong-un also visited Beijing to personally meet Chinese President Xi-Jinping in March. The March visit was a first known visit by Kim Jong-un outside North Korea borders since 2011.

Meanwhile, Kim Jong-un also made an announcement for closing down its nuclear test site ahead of the Korea-summit with South Korea President Moon Jae-In and will be followed by a planned face-to-face with US President Donald Trump.