Colonel Khun Okkar said the invitation to Daw Aung San Suu Kyi to watch the signing of the agreement after it was agreed between the NCCT and the Union Peace-making Work Committee was not based on her political role.
Daw Aung San Suu Kyi would be invited to witness the signing of the agreement in her capacity as an internationally respected leader not as a representative of the National League for Democracy, Colonel Khun Okkar told journalists at the Myanmar Peace Center in Yangon.
He also said the government had not responded to a proposal by the NCCT for the NLD leader to participate as a mediator.
"We have invited Daw Aung San Suu Kyi to take part as a mediator but the government has not responded and a mediator must be invited by both sides," said Colonel Khun Okkar, from the Pa-O National Liberation Organisation.
NLD central executive committee member U Nyan Win said that if Daw Aung San Suu Kyi was invited by name she would attend but otherwise the party would send its representative.
"She has not been invited officially, so she has not attended the talks," U Nyan Win said.
A senior official at the Myanmar Peace Center, U Hla Maung Shwe, told Mizzima on August 18 that UPWC chief negotiator U Aung Min had never raised objections about who should participate in the peace process.
The latest developments follow significant progress at the last round of negotiations between the NCCT and the UPWC at the peace center from August 15 to 17, with only four points of the draft ceasefire still in contention.
The next round of talks is due to take place next month.