Seoul, Jul 11 (IANS): South Korea and the US appear increasingly likely to scale back or even call off a major combined exercise due to the COVID-19 pandemic, after indefinitely postponing their annual springtime drill earlier this year, sources said on Saturday.

"Both sides share the need to stage the summertime exercise as planned, and we've continued consultations on the matter. But things are highly flexible due to the COVID-19 situation," Yonhap News Agency quoted a Defence Ministry official as saying.

Seoul and Washington usually carry out major combined exercises twice a year -- in around March and August.

But they postponed this year's springtime exercise due to COVID-19, and it has not been held to date, as the health crisis continues.

"It already seems practically impossible to push for the summertime exercise normally, given that the US has not taken action for the troop deployment to South Korea necessary for the exercise," a source said.

"Most of the US members mobilized for an exercise are reserve forces, which means they have their jobs. Putting them in weeks-long isolation is far from easy," he said.

"The adjustment or cancellation seems to be a plausible option."

All overseas visitors to South Korea are required to be quarantined for two weeks due to the coronavirus.