But even before Jang's execution, it was unclear how far Pyongyang was willing to go.
The North has shown no willingness to abandon its nuclear weapons program to get out from under international trade sanctions. That makes investment or financing from major international organizations difficult if not impossible.
It also means the success of the zones hinges on China, North Korea's only major ally, and Jang was seen as a crucial conduit between Pyongyang and Beijing, along with being a supporter of China-backed reforms, such as the zones, to revive the North's moribund economy.
Jang met with top Chinese officials during their visits to Pyongyang, and in 2012 traveled to China as the head of one of the largest North Korean delegations ever to visit the Chinese capital to discuss construction of the special economic zones, which Beijing hopes will ensure North Korea's stability.
Yun, however, downplayed Jang's importance in policymaking and said his removal would instead speed progress on the economic front because he was a threat to the unity of the nation. He said Jang's execution should not scare away Chinese investment, which is crucial to the success of the zones.
"By eliminating the Jang Song Thaek group, the unity and solidarity of our party and people with our respected marshal at the center has become much stronger, our party has become more determined and the will of our soldiers and people to build a prosperous socialist country has been strengthened," Yun said. "Our State Economic Development Committee welcomes investment and business from any country to take part in the work of developing our new economic zones."
Yun said local officials have been tasked with drawing up the plans for the zones in their jurisdictions and are likely to formally submit them for approval to his commission within the next few months.