The outgoing South Korean ambassador to China hoped Wednesday that his country's relations with China, which have been strained over a US missile defense system, have already bottomed out and will only improve going forward.

Kim Jang-soo said he feels sorry for Korean people, businesses and small merchants hit hard by the fallout from the prolonged feud over the deployment of the Terminal High Altitude Area Defense system to South Korea.

"I just hope that while I was there, things had already bottomed out and will improve under the incoming ambassador," Kim told Yonhap News Agency upon arriving at Gimpo International Airport in Seoul from Beijing. 

Kim, a former defense minister and head of the National Security Council, had served as the country's top envoy in Beijing for about 30 months starting in 2015. He is to be replaced by Noh Young-min, a politician known for his expertise on China.

Relations between South Korea and China have been strained since Seoul announced in July last year it would allow the United States to deploy a THAAD battery on its soil in a bid to better counter North Korea's growing missile threats. China has strongly opposed the move, claiming that it hurts its strategic security interests.

In what appears to be a retaliatory step, China has toughened its regulatory enforcement, apparently targeting South Korean firms and products. The Beijing government has denied any official involvement.

"I have nothing to say, but I feel sorry for our people, businesses and small merchants in China," Kim said. Asked what area he could have done better in as ambassador, he did not hesitate, saying, "It was THAAD."

Kim remained optimistic that the two will eventually resolve the THAAD feud, as both are trying to find "common ground."

"As a result of the THAAD issue, South Korea-China ties have been going through a tough time," he said, "but given that all involved are concerned about this issue, they are now on track to find common ground." (Yonhap)