"We were hoping against hope that the solution will come before the election," he said.
Rio was speaking on the occasion of the completion of one year of his People's Democratic Alliance (PDA) government of which the BJP is a part.
A new government, which came to power in Nagaland under Rio early last year, had raised hopes of a solution to the Naga political problem.
Earlier Sunday in Delhi, the Election Commission announced that the Lok Sabha election will be held from April 11 to May 19.
The government and the Naga people now do not know what the negotiating parties are thinking, Rio told reporters without elaborating it.
"If it (Naga political solution) does not come...it will be problem for our Naga society to carry on," the chief minister said.
Even after the signing of the framework agreement with the NSCN(IM) in 2015 and six Naga nationalist political groups joining the peace talks separately, there has not been a breakthrough on the decades-old Naga problem.
The PDA, comprising 17 Nationalist Democratic Progress Party (NDPP) MLAs, 12 BJP, 2 NPP and one JD(U) and an Independent, came to power after defeating the 15-year-old Naga People's Front government in the 2018 assembly election.
Thanking the allies, Rio said, "We could not have made it, unless we received firm support from our alliance partners."
"We promised to bring change (before the assembly poll), but the change has to start from the attitude and mindset of the people towards positivity," he said.
He said a move towards plastic-free state and initiatives of tobacco-free villages and green villages are positive changes and such initiatives will bring positivity.
"Real change will happen when we all come together in unison with the singular purpose of changing our society for the better," the chief minister said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)