Amid indications of a hardening in the National Socialist Council of Nagalim-IM's stance, the rebel group's leadership is likely to meet government representatives in New Delhi on July 21-22 for talks to carry forward the peace process and extend the ceasefire in Nagaland that ends on July 30.

NSCN-IM chairman Isak Chisi Swu and general secretary Thuingaleng Muivah will met a Group of Ministers led by Union Minister Oscar Fernandes and the interlocutor for Naga talks, K Padmanabhaiah, to discuss matters like the extension of the 10-year-old ceasefire, the group's demand for unification of Naga-inhabited areas and bitter clashes between rival Naga factions.

"This time, we want something concrete from the government on our demands. Otherwise it is futile to meet only for the extension of the ceasefire," NSCN-IM spokesman Tongmeth Wangnao Konyak told PTI on phone.

The NSCN-IM submitted a charter of demands to the government, including a separate constitution for Nagaland, a 'new and unique' relationship with New Delhi and unification of Naga-inhabited areas of Manipur, Arunachal Pradesh and Assam.

However, these three states have rejected this demand. The government too has not made any commitment on the issue so far.

"The unification of Naga areas is a must. Without unification, there will be no solution," Konyak said.

At a meeting in Bangkok last year, before extending the ceasefire for a year, both sides agreed on a broad framework to define a relationship that could end the Naga insurgency.