The policy of pursuing nuclear weapons in tandem with economic development by North Korean leader Kim Jong-un is doomed to fail, a state-run Chinese newspaper said Wednesday, calling the North's nuclear ambitions a "poison" for its economy.

North Korea's just-concluded party congress officially endorsed Kim's "byeongjin" policy of simultaneously pursing both nuclear and economic development, dashing hopes that Kim may chart a different course on its nuclear weapons program.

In an editorial, the state-run China Daily newspaper said Kim's policy "does signify a step forward from songun," or the military-first policy by his late father, Kim Jong-il.

"But it is simply beyond Pyongyang's competence to pursue the twin goals at once. The country's limited resources can't support both. Nor will the international community allow its nuclearization," the editorial reads.

The Chinese paper said Kim "appears unaware that his nuclear ambitions are poison for his country's economy."

"They will not only exhaust his country's very limited resources but will further isolate his country from the rest of the world, politically and economically," it said.

North Korea has conducted four nuclear tests since 2006. The latest nuclear test in January prompted China to back tougher U.N. sanctions against the traditional ally.

Further consolidating his grip on power, Kim was elected chairman of North Korea's ruling Workers' Party during the party conclave, which was held for the first time in 36 years.

Chinese President Xi Jinping sent a congratulatory message on Monday to Kim on his promotion, hoping to steadily develop the friendship between the allies. (Yonhap)