"The plan for the THAAD installation should be enforced as quickly as possible to minimize any fallouts," Kim Hyun-wook, a professor at the Korea National Diplomatic Academy, told a seminar hosted by a local think tank.

"We should have been more careful in making the decision at first, but once the decision was made, its withdrawal would have a negative impact on our diplomatic relations both with the US and China," he added.

China has been stepping up its pressure on South Korea since its July decision and trying to make it rescind the plan through diverse channels. Though it is denying any official involvement, Beijing has taken what many see as retaliatory actions, such as toughening rules and regulations zeroing in on Korean firms and products.

The Seoul government recently said it is exploring countermeasures against what is viewed as retaliatory action against its products, including referring the matter to the World Trade Organization.

Some experts have been calling for a swift THAAD installation to made clear that there is no turning back in its decision and eventually dash any hope China might have in making the two allies take back their joint decision. (Yonhap)