Top leader of the Democratic People's Republic of Korea Kim Jong Un, has said the nation will only use its nuclear weapons if its sovereignty comes under threat from another nuclear power.

The announcement came in a report delivered at the ruling Workers' Party of Korea's Congress. Kim also promised that the DPRK will follow a policy of non-proliferation.

He said Pyongyang is willing to improve and normalize relations with countries that had been "hostile" in the past.