Agent Lee Yeung Joong said: "I am currently negotiating with some clubs in the UK, Germany and other countries.
"Those clubs include Cardiff City who have shown assertive attitudes for the transfer of Kim Bo-Kyung. Their manager Malky Mackay really likes Bo-Kyung and negotiations are progressing satisfactorily.
"The transfer fee being discussed is at a level of 3m.
"I also have contacted Celtic through my sub-contracted agent who is working in Scotland.
"But I have not received any official bid from Celtic.
"I will leave door open for his transfer and consider every possibility with clubs who have interests about Kim Bo-Kyung.
"I aim to complete his transfer matter before the Olympic tournament starts to avoid disruptive influences for Korea Under-23 national team."