Former prime minister P V Narasimha Rao understood best the cause of the National Socialist Council of Nagalim (Isak-Muivah), the group's spokesman V S Atem said on Friday.
Rao had met NSCN (I-M) chairman Isak Chishi Swu and general secretary T Muivah in Switzerland in 1993.
"If you are asking us which prime minister helped us the most, I would say it was former prime minister P V Narasimha Rao. Before him, the government of India had treated the Nagaland problem as a problem of insurgency. It was Rao who understood that it is a political problem," Atem told newspersons in New Delhi.
Atem claimed progress has been made in the group's substantive talks with the Centre over the last two years. "Our collective leadership has been making courtesy calls on the Indian leadership. We appeal to the government of India, the Indian leadership, the civil society and the media to understand the Naga issue in the right perspective, in the larger interest of the people of India and Nagalim.
"The Indian government is willing to show flexibility and we in turn are willing to associate ourselves with the Indian government and the Indian people," he said.
He ruled out negotiations with the government within the framework of the Indian Constitution.
Asked if the outfit would be able to carry along the Kuki Nagas who are opposed to them, Atem said the group's leadership is in touch with not only the Kukis but also with Meitei Nagas. "We have been talking to them and we will be able to carry them with us," he said.