Responding to Washington's ongoing public aversion to North Korea sanctions relief, a director of the foreign ministry-linked Institute for American Studies warned that Pyongyang may reconsider Kim Jong Un's April 2018 directive to focus exclusively on economic development.
In the latest case, an agreement was reached between South Korean President Moon Jae-in and DPRK leader Kim Jong-un at their summit last September.
But little progress has been made since then, with Washington pushing to maintain sanctions against the North until its "final, fully verified denuclearization" and Pyongyang condemning USA demands as "gangster-like".
"The fact that the commentary was written by a low ranking official suggests that North Korea does not want to walk away from the current setting for the talks", said Dr. Cheong.
"We start with the ongoing diplomacy with North Korea".
The biggest combat-readiness war game ever staged in and around Japan has gone ahead, however, with nuclear-powered aircraft carrier USS Ronald Reagan joining Japanese destroyers and a Canadian warship in the ocean off Japan - another key player in the effort to pressure North Korea.
However, in August of this year, the independent experts produced a report to the Security Council of the United Nations (UN), which indicated that North Korea stopped developing nuclear and missile programs.
"The US thinks that its oft-repeated "sanctions and pressure" leads to "denuclearisation". Somewhat earlier edition of the Washington Post reported that according to US intelligence, North Korea has built a new missile.
"The word byungjin could be added to our policy line of focusing on building economy", the Foreign Ministry said in a statement, released under the name of the director of the ministry's Institute for American Studies.
"A lot of work remains, but I'm confident that we will keep the economic pressure in place until such time as chairman Kim fulfils the commitment he made to President Trump back in June in Singapore", he said.
Among major countries dealing with the North Korean nuclear issue, Japan is the only one to have been kept at arm's length since Pyongyang began a string of diplomatic engagements this year.
Information for this article was contributed by Jihye Lee of Bloomberg News; by Simon Denyer of The Washington Post; and by Kim Tong-Hyung of The Associated Press.