"So there doesn't have to be a train wreck over North Korea policy", he told AFP.
A former national basketball captain and the North's sole International Olympic Committee member, Chang stressed that so-called sports diplomacy takes months of painstaking preparations and political coordination.
The Games in Pyeongchang, South Korea, will take place from 9-25 February. Moreover, despite Washington's frustration with Moon's decision on THAAD - the Trump administration needs South Korea, in addition to other regional players like Japan and China, on board to follow through on its approach to Pyongyang.
Mr Moon has already expressed willingness to travel to Pyongyang and to restart stalled inter-Korea exchanges on the humanitarian, sports and economic fronts.
Officially, the delay is to allow for a new, comprehensive environmental impact assessment, but analysts say the move is a strategic one by Moon to delay the tricky diplomatic situation he inherited.
Local newspapers have warned that such initiatives to appease Pyongyang could be premature, and worse, damage relations with the US. The stakes will be especially high because Moon - a progressive with dovish tendencies towards Pyongyang - is looking to demonstrate unity with President Trump without sacrificing his own policy goals of engaging the North diplomatically.
Participation in Pyeongchang could "provide a turning point for the reconciliation between the South and North", Moon said.
Hours after the president sent out the tweet, Secretary of State Rex Tillerson and Defense Secretary Jim Mattis met with Chinese Secretary of State Yang Jiechi, and a member of the Chinese Central Military Commission Gen. Fang Fenghui, to discuss the North Korean issue.
South Korea's Unification Ministry said Monday it was "expecting" North Korea to agree to form a joint team at next year's first Winter Olympics on the peninsula, Turkey's Anadolu (AA) news agency reported.
Addressing an audience of former US officials, including former Director of National Intelligence James Clapper, Kang Kyung-hwa said Seoul remains committed to deploying THAAD and working closely with the United States. To wrap up the conference, participants will adopt a joint declaration on working together for shared prosperity across the Eurasian continent.