North Korea's military parade marking the Workers Party's 70th anniversary on Saturday cost the impoverished country an estimated US$1 billion, roughly one third of its annual budget.

That means Pyongyang's dependence on exports to China in return for hard currency is going to increase even further.

But its exports to China fell almost 10 percent in August on-year amid an economic slowdown in the world's most populous country.

According to the Wall Street Journal, this could spell t rouble for leader Kim Jong-un as foreign reserves are used to raise the living standards of the country's elite -- vital for maintaining his grip on power.

It added such a scenario could put the leader in a vulnerable position, although possible repercussions will be hard to detect due to the reclusive regime's opaque economy and political system.