The Thai premier, accompanied by Deputy Premier/Education Minister Phongthep Thepkanchana, Deputy Premier/Foreign Minister Surapong Tovichakchaikul, Defence Minister Sukumpol Suwanatat and Minister Attached to the Prime Minister's Office Sansanee Nakpong, left Bangkok early Monday morning for Phnom Penh.
The former Cambodian monarch died at age 89 of a heart attack in Beijing on October 15 last year.
Leaders of the ten-nation Association of Southeast Asian Nations attended the ceremony today in the Cambodian capital, along with Chinese, Vietnamese and French leaders.
Speaking to reporters before his departure, Mr Phongthep said the Thai leader is scheduled to hold bilateral talks with Cambodian Prime Minister Hun Sen.
The deputy premier said the Preah Vihear dispute will not be discussed during the talks as the issue is now being considered by the International Court of Justice (ICJ).
Mr Phongthep pledged that the Thai delegation will do their best to defend the case at the ICJ. He will go to the United Kingdom this Wednesday with the Thai legal team, to meet with foreign lawyers in preparation for the case as Thailand must make a closing statement at the ICJ in April.
Ms Yingluck said before leaving Bangkok that she is not certain as to whether the bilateral talks could take place with her Cambodian counterpart as the main purpose of the visit is to attend the cremation of the late King Father