Sovereignty of Naga tribal rebels, fighting India's oldest insurgency, would be the core issue at talks beginning in Bangkok on Friday even though a six-month ceasefire extension is due to expire on July 31, a top leader said.
"Extension of ceasefire is not on the main agenda at the coming round of talks," Rh. Raising, a senior leader of the National Socialist Council of Nagaland, Isaac-Muivah faction (NSCN I-M), told Reuters in an interview.

"The focus of the coming round of talks in Bangkok will be on the federal relationship between two entities -- India and the Nagas," Raising said late on Sunday in Dimapur, the commercial hub of Nagaland state.
Naga rebels have been fighting since 1947 for a separate homeland that includes parts of the predominantly Christian state of Nagaland as well as some neighbouring states inhabited by the tribals.

More than 20,000 people died in the insurgency until a ceasefire in 1997 and the rebels and the Indian government have held several rounds of talks since.
But there has been little progress on the central rebel demands -- unification of Naga-dominated areas in northeast India, which is fiercely opposed by other ethnic groups in the region, and ultimately independence.

Security analysts say peace with the Nagas is crucial for a broader peace in the remote northeast, seven states connected to the rest of India by a thin strip of land and home to dozens of insurgent groups.

Raising said the two-day talks with Indian government ministers in Bangkok would fail if New Delhi refused to recognise their right to self-determination.
"Our federation can't exist within the Indian union or under the Indian constitution," said the bespectacled rebel leader.

"We are for independence, nothing else will satisfy us. Ours is a basic issue where the survival of Nagas as a nation is at stake," the school teacher-turned-rebel leader said.
Analysts say although a return to conflict is unlikely with most NSCN cadres getting used to a life of peace under the truce, the inability of talks to make progress would hurt stability in the region.

"We don't hate India and will maintain a good relationship with India in many areas like defence and economy," Raising said. "But there will be no merging in culture and polity."