Chairman Isak Chishi Swu and General Secretary Thuingaleng Muivah of the National Socialist Council of Nagaland (NSCN) arrive in New Delhi on Sunday from Bangkok and will meet Singh and India's home (interior) minister next week.

The two rebel leaders live in Thailand.

The NSCN has been fighting for an independent homeland for an estimated three million Naga tribesmen for over four decades. The revolt has killed more than 20,000 people.

"They are coming to Delhi with an aim to solve the problem; as you know the peace process has been going on for the last seven years," said NSCN spokesman Kraibo Chawang from Dimapur, the commercial centre of Naga-dominated Nagaland state.

In 1997, New Delhi and the NSCN signed a ceasefire pact which has held. The two sides have had several rounds of talks in Thailand and Europe but the dialogue has not produced any breakthrough.

Muivah and Swu met Indian officials in New Delhi in 2003 for the first time but talks stalled over India's refusal to agree to their demand to unify all Naga- dominated areas in the remote northeast into a "Greater Nagaland".

"These talks are important, not only for the people of Nagaland but also for the fact that other insurgent groups will be looking to see how this dialogue progresses," K Padamanabhaiah, the government's key negotiator, told Reuters.

"We are wishing for a breakthrough," he said without elaborating.

India's largely mountainous northeast is home to over 200 ethnic and tribal groups.

More than two dozen insurgent groups operate in region, fighting for independence, more tribal autonomy or statehood.

The groups accuse New Delhi of taking away the region's resources like oil, tea and timber and neglecting the local economy.

The Naga revolt is the oldest in the northeast region, connected to the rest of India by a strip of land less than 30 km wide, and the NSCN demand for a greater Nagaland has angered other tribal and ethnic groups who fear domination by the Nagas.

Of the estimated three million Nagas, two million live in Nagaland and the rest are scattered over the surrounding states of Manipur, Assam and Arunachal Pradesh. Some live across the border in northern Myanmar.