NPCC General Secretary (administration) Medokhul Sophie in a statement said that the decision was taken during the first formal executive meeting of the party after the February 23 electoral debacle held in Dimapur yesterday.
The meeting resolved to act as a 'strong opposition party' keeping in view the 'welfare and well being of the people as its utmost priority, he said.
The meeting also resolved to look forward to get support of the people of Nagaland as it ventured to strengthen the party at all levels more vigorously in future.
State Congress President S I Jamir, on behalf of the party, congratulated Rio on assuming the office of the Chief Minister of Nagaland for the third consecutive term.
In his message, Jamir expressed hope that under the leadership of Rio, the state would see tremendous progress on all fronts.
The NPCC President also assured of all possible support of the Congress to the new government.