SEOUL--South Korea and the United States will kick off their annual joint military drills this week but without mobilizing U.S.-based troops after scaling back the program due to coronavirus concerns, South Korean media reported on Wednesday.

The allies have been discussing how to adjust the exercises, which usually begin in August, with the coronavirus threatening to disrupt the travel of U.S. personnel.

The program involves tens of thousands of soldiers from both sides, though largely focused on computerized simulations rather than live field training.

The exercises will be held from Aug. 16-28 but in a reduced scale, though the timeframe was extended by a couple of days to disperse participants and minimize night activities, the Yonhap news agency said.

Seoul’s defense ministry spokesman said the plans have not yet been finalized. The U.S. Forces Korea (USFK) did not immediately respond to a request seeking comment.

The 28,500-strong USFK has reported at least 65 COVID-19 cases among its troops, employees and their families since July, prompting concerns among some South Korean residents near their base. All were confirmed upon arrival or while in two-week mandatory quarantine.

The combined drills are closely monitored by North Korea which calls them a "rehearsal for war" and had already been reduced in recent ears to facilitate U.S. negotiations aimed at dismantling Pyongyang’s nuclear programs.

This year’s exercises also provide a chance to assess South Korea’s readiness to take over wartime operational control (OPCON), and the change could affect President Moon Jae-in’s pledge to complete the transfer before his term ends in 2022.

The United States agreed to hand it over if conditions are met, and the allies will make a decision after three rounds of capability tests, the first of which was done last year.

The JoongAng Ilbo newspaper reported Washington had informed that it would not bring evaluators because of coronavirus concerns, which could make it difficult for this year’s test to be fully conducted.