Commerce Department added that "We will engage directly with PRC (People's Republic of China) authorities to detail our position and clarify their action.
Under South Korean law, doctors are restricted from striking, and the health ministry has asked police to investigate people connected to the work stoppage.
As part of a team led by South Korean defense prime Hanwha, which recently won the award for Phase 3 of Australia's Land 400 infantry fighting vehicle, Plasan will have a working presence Down Under.