North Korea is calling for the spirit of self-rehabilitation as the regime-declared "80-day battle" to overcome economic hurdles nears its end.

The North's ruling party mouthpiece Rodong Sinmun on Monday stressed that self-reliance is the only thing North Koreans can trust, adding that no other country is willing to lend a helping hand or genuinely wish for the reclusive state to become powerful and prosperous.

The paper said the historical lesson from past socialist movements is that "prizes obtained from the bloody revolution" can be lost overnight if one fails to gain power while relying on others.

Pyongyang is set to reiterate such calls when it is expected to announce a five-year economic development plan and foreign policy directions at a rare congress of the ruling Workers' Party next month.

A South Korean Unification Ministry official, meanwhile, told reporters on Monday that the 80-day campaign, which is believed to have started on October 12, will likely end on December 30.