North Korean leader Kim Jong Un has ordered his county's military, munitions industry and nuclear weapons sector to accelerate war preparations to counter what he called unprecedented confrontational moves by the U.S., state media said on Thursday.

Speaking on the policy directions for the new year at a key meeting of the country's ruling party on Wednesday, Kim also said Pyongyang would expand strategic cooperation with "anti-imperialist independent" countries, news agency KCNA reported.

"He (Kim) set forth the militant tasks for the People's Army and the munitions industry, nuclear weapons and civil defence sectors to further accelerate the war preparations," KCNA said.