He also called upon the people of Assam to use their collective wisdom to persuade the banned outfit to give up the path of insurgency and confrontation for the sake of development of the state.
A section of the ULFA has already declared unilateral truce with the government to facilitate direct talks between the outfit's top brass and representatives of the government in near future to find a solution to the problem.
The PM, however, made no reference to this development.
"I have said on a number of occasions that power in a democracy flows from the ballot rather than from the bullet and that all grievances of the people of Assam can be addressed effectively in our democratic polity. I, therefore, call upon the ULFA to join the national mainstream and work with all of us for rapid social and economic development of Assam," Singh said.
His speech was read out in absentia at Nagaon in central Assam by Dip Gogoi, the Congress MP from Kaliabor Lok Sabha constituency and brother of Assam chief minister Tarun Gogoi.
Dr Singh could not attend the scheduled public rally in Nagaon as his aircraft could not land due to bad weather.
Singh further said, "The North East has immense development potential and we will make every effort to ensure that it is realized. However, the continued activities of insurgent groups create a climate of fear and insecurity not conducive to rapid economic development and new investment in Assam and other North Eastern States."
The PM highlighted the need to tap region's vast water resources collectively by all the states for achieving rapid economic growth. "In exploiting the hydro-power potential in the region, the interests of all States of the North-East will have to be harmonized. I am happy to know that there is now a consensus emerging on my suggestion of setting up a North Eastern Water Resources Authority to plan and implement the use of the mighty waters of this region," he said.
The PM claimed that the UPA government was giving high priority to address the problem of lack of adequate infrastructure in the North East was and there would be substantial investment in the Eleventh Plan in infrastructure sector in the region.