According to the report, the drills are scheduled to take place from 16-28 August.
South Korea's preparation reportedly began on Tuesday and included a crisis management staff training.
Last February, South Korea and the US suspended the Key Resolve, Foal Eagle and Ulchi-Freedom Guardian joint military drills and replaced them with the biannual Dong Maeng exercise.
Dong Maeng was originally supposed to engage real troops and military equipment, albeit of reduced quantity, but so far has come down to computer-simulated military command post-exercise. Because the pandemic has complicated the arrival of US troops, the government reduced the exercise's format even further this year, cancelling the night-time training.
The March edition of the Dong Maeng military exercise was cancelled earlier this year due to COVID-19.