SEOUL: South Korea's trade minister said on Sunday the government's responses against discriminating action by China towards South Korean firms will be strengthened and he feels "deep concern" over recent measures taken by Beijing.

South Korean Trade Minister Joo Hyung-hwan made the statement while visiting the United States, the ministry said in a statement.

South Korean media said last week Chinese government officials had given verbal guidance to tour operators in China, to stop selling trips to South Korea days after the Seoul government secured land for a US missile-defence system from Lotte Group.

China objects to the missile-defence system.