Jang Song Thaek's wife, meanwhile, has been named to an ad-hoc state committee, the country's official media reported, an indication that Jang's execution has not immediately diminished her influence.
The execution Friday of Jang, considered to be North Korea's second most powerful man and a key architect of the country's economic policies, should not be taken as a sign that the North will change its economic course or its efforts to lure foreign investment, Yun Yong Sok, a senior official in the State Economic Development Committee, said in an interview with The Associated Press in Pyongyang.
Luring foreign investment is critical to garnering badly needed foreign currency and funding for infrastructure projects so the Kim regime can live up to its promise of raising the impoverished nation's standard of living.
"Even though Jang Song Thaek's group caused great harm to our economy, there will be no change at all in the economic policy of the Democratic People's Republic of Korea," Yun said. "It's just the same as before."
Jang's sudden purge and execution for allegedly trying to overthrow the government has raised questions about how solid the North Korean regime is and whether it will be able to stay the course on policies aimed at raising the country's standard of living.
Last month, North Korea announced plans to create in each province special economic zones, which are like incubators for introducing capitalist methods into the North's tightly controlled, command economy. The North also recently laid out new laws to facilitate foreign tourism and investment. The laws provide foreign investors with special incentives and guarantees, while giving local leaders greater autonomy to promote themselves and handle business decisions.
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.
Jang was considered the second most powerful man in North Korea before his fall, which was announced last week and followed days later by his execution for a long list of anti-state crimes, including building a power base of his own to rival and possibly overthrow Kim and the ruling Workers' Party.
His removal leaves no clear No. 2 under Kim, whose inner circle now includes Vice Marshal Choe Ryong Hae, Premier Pak Pong Ju and the ceremonial head of state, Kim Yong Nam.
In an interview aired Sunday on ABC's "This Week," U.S. Secretary of State John Kerry said Jang's execution is "an ominous sign of the instability" of North Korea and underscores the urgency of denuclearizing the Korean Peninsula.
"To have a nuclear weapon, potentially, in the hands of somebody like Kim Jong Un just becomes even more unacceptable," Kerry said.
What will happen next in Pyongyang remains unclear, but North Korea watchers will be closely following the second anniversary of Kim Jong Il's death on Tuesday for clues. Of particular interest is whether Jang's wife, Kim Kyong Hui, the younger sister of Kim Jong Il, will be present in official ceremonies.
Her name appeared in a state media dispatch late Saturday alongside top officials on a funeral committee for fellow senior Workers' Party official Kim Kuk Thae, who died Friday.
Kim Kyong Hui, 67, has risen through the ranks in recent years and holds a slew of top posts. Analysts said the dispatch suggested that her political standing hasn't been immediately affected by her husband's execution and that she may have even given her nephew the green light to fire Jang - but not to have him executed.
"She may have opposed Jang's death sentence, but she could have agreed on Jang being dismissed," said analyst Hong Hyun-ik from the private Sejong Institute in South Korea.
Kim and Jang, who married in 1972, had a dysfunctional marriage in recent years, and their only daughter committed suicide in 2006 while studying in Paris, according to South Korean media reports.
Hong said that if her health condition allows it, Kim Kyong Hui is expected to join other top officials at Tuesday's ceremonies marking the second anniversary of Kim Jong Il's death.
Kim Kyong Hui's public activities have been sharply reduced in recent months amid media reports that she suffers liver, heart and other ailments.