A top aide to the North Korean leader Kim Jong-un has died in a car crash, state news agency KCNA has said.

Kim Yang-gon, 73, was a secretary of the ruling Workers' Party and was in charge of ties with South Korea.

He was part of a high-level delegation from North Korea that helped ease a stand-off with the South in August, after an exchange of artillery fire.

The state news agency called him Kim Jong-un's "closest comrade and a solid revolutionary partner".

"Comrade Kim Yang-gon, a Workers' Party secretary and member of the party Central Committee Politbureau... died in a traffic accident at 6:15am, Tuesday, at age 73," KCNA said, without giving details.

It added that Kim Jong-un would lead an 80-member state funeral for Kim on Thursday.

Tension between North and South Korea increased in August when a border blast injured two South Korean soldiers.

Meetings at that time eventually led to the two countries stepping away from a military confrontation.