"The government is working to confirm whether the reports are true," the foreign ministry said in a message sent to reporters.

"If they turn out to be true, we think it would be very regrettable in that Beijing is artificially curbing the ordinary exchange of people."

"Under no circumstances should there be any action that would cause artificial roadblocks to stand in the way of the exchange of the two countries' peoples, which is the basis for bilateral relations," it added.

In July, South Korea and the US unveiled their plan to place a THAAD battery on the peninsula within this year to better guard against the growing missile threats from North Korea. China strongly objects to the move, saying that it hurts its strategic security interests.

China has been increasing its pressure on South Korea to make it drop 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 its regulators zeroing in on Korean firms and products.

The travel ban came especially after South Korea's military signed a deal with a local conglomerate to secure land for THAAD earlier this week, raising expectations that the installation process will pick up pace.

Industry data showed that Chinese tourists account for nearly half of the number of foreigners visiting South Korea every year.

The ministry said that it will keep "every option" on the table in drawing up its own countermeasures through close cooperation with other relevant agencies against any retaliation against THAAD.

"We have delivered our stance (on this matter) several times through diplomatic channels and we will keep making such efforts going forward," the ministry added. (Yonhap)