"Comrade Kim Yang-Gon, a Workers' Party secretary and member of the party Central Committee Politbureau... Died in a traffic accident at 6:15 am yesterday at age 73," the North's Korean Central News Agency (KCNA) said.
KCNA said leader Kim Jong-Un would head an 80-member state funeral for Kim tomorrow.
A career party diplomat, Kim has been known as a key confidante to the leader in the Stalinist state, advising him on inter-Korean relations and more recently on international relations in general.