"It will signal that the new regime, like its predecessors, has chosen bombs over electricity" for its impoverished population, Hecker wrote.

Another test also increases concerns about where North Korea's nuclear material will end up in the long term, either because it decides to sell it or in the event of a collapse of the regime, according to Yun of the Ploughshares Fund.

"That's something that we really have to be concerned about," he said.