He said the government merely wants to hear Mr Ban's experiences of mediating conflicts in other countries.
Mr Surapong was speaking on Friday in response to opposition to Mr Ban's invite, raised in the form of an open letter circulated at the Foreign Ministry and on social media.
The one-page letter expressed strong disagreement by ministry officials to Mr Surapong's plan. It was signed by about 70 ministry officials who argued it would be an interference in Thailand's internal affairs if Mr Ban was to mediate the conflict.
The letter is believed to have been written by lower-ranking Foreign Ministry officials.
Mr Surapong said the ministry’s officials misunderstood that he would invite the UN secretary-general to act as a mediator.
He only wants Mr Ban to come and share his experiences with other countries' internal conflicts.
“I don’t want to have disharmony in Thailand and I stress that this invitation is not a political intervention,’’ said Mr Surapong, adding that it is better than allowing the UN to come after the situation gets out of control, such as in Ukraine.
Mr Surapong said he would not consider any disciplinary action against the officials who signed the letter as they were entitled to freedom of expression.
“All state officials must show that they perform their professional duties without political involvement," he said. "The invite for Mr Ban to come to Thailand was made in consultation with Permanent Secretary for Foreign Affairs Sihasak Phuangketkeow.
"Civil servants misunderstood that I did not listen to his opinion. I listened to him today and have clarified with him what the officials [who wrote the open letter] did not understand."
Mr Surapong said he is waiting for confirmation of Mr Ban’s visit to Thailand, and if it is confirmed, he will invite Suthep Thaugsuban, leader of the anti-government People’s Democratic Reform Committee, to join the meeting and exchange opinions.