In their assessment, a USA official confided under the condition of anonymity that the new rocket being tested by North Korea could be a key component of an intercontinental ballistic missile (ICBM) engine.
"If the neighbouring countries in northeast Asia, including North and South Korea, can host the World Cup together, it would help to create peace", Moon said. However Chang Ung, the sole North Korean representative for the International Olympic Committee, who is part of the visiting delegation, was quick to lower expectations.
But when asked about the suggestions, Chang said he was not in a position to talk about them.
He was speaking after South Korea's sports minister was quoted as saying some skiing events for the 2018 Pyeongchang Olympics could be held in North Korea, although officials insist he was misunderstood.
The two Koreas made a joint entrance in the 2000 Summer Sydney Olympics but never formed a united team for the global sporting event.
Taekwondo is a Korean traditional martial art but has been the subject of a bitter North-South rivalry.
Lee said the North "should stop developing missile and nuclear programmes and come out on to the path of denuclearisation on the Korean peninsula".
There are two worldwide federations: the South Korea-based World Taekwondo Federation recognized by the global Olympic Committee and the North-backed global Taekwondo Federation.
Former Assistant Secretary of State Christopher Hill made the point in a recent Project Syndicate article, expressing concern about the "freeze-for-freeze" idea that calls for the U.S. freezing or scaling back the exercises in exchange for the North freezing nuclear and missile testing. "President Moon's visit to the Agency for Defense Development today sends a stern warning about North Korea's series of recent provocations".
South Korean intelligence services told lawmakers recently that the moves of US and South Korean forces make Kim "extremely nervous", according to the Korea Herald.
Moon also said South Korea, like the United States, hopes to "engage in dialogue" with North Korea, though "regarding exactly how, we do not have a detailed way forward". Given its partnerships with Iran on nuclear weapons and missiles, it's even questionable whether North Korea is susceptible to deterrence.
Choue Chung-won, director of the World Taekwondo, said the North Koreans will stay for the duration of the games. USA forces would have to navigate air defenses in one of the most heavily protected spaces on earth as well as risking a nuclear response even if their mission is successful.