The 48-hour deadline given by the governor to Mr Rio and Mr Zeliang to submit the signatures of the elected members supporting them will expire on Tuesday evening.
Governor Acharya told The Telegraph on Sunday night in a text: "I have requested Mr Rio to give me the letters of support signed by all 18 elected NDPP MLAs".
As the combination of the BJP and the NDPP is the largest entity in the newly elected Assembly, it is likely that this alliance is invited by the Governor to form the next Government. BJP Nagaland unit president V Lhoungu said the party's MLAs chose to go with the pre-poll alliance partner, the NDPP, during a meeting in Dimapur on Sunday evening.
According to NDPP sources, the lone successful Independent candidate, Tongpang Ozukum from Angetyongpang constituency in Mokokchung district, has pledged support to the NDPP-BJP alliance and to the leadership of Mr Rio.
BJP and NDPP together bagged 30 seats.
Kikon said the incumbent Chief Minister Zeliang was in close touch with the BJP high command as the party wanted to continue the alliance "in the interest of the peace process".
On BJP severing ties with NPF, the MLA said it would indicate that the saffron party was scared of its slogan "Election for solution" as only a stable government could pursue the issue effectively.
In the final result of the Nagaland Assembly elections, Bharatiya Janata Party (BJP) has won 11 seats, while Nationalist Democratic Progressive Party (NDPP) 16, National Development Front (NDF) 27 and others four seats.
Mr G Kaito Aye, JD (U) candidate from Satakha assembly segment, defeated Zheito Chophy of NPF by a margin of 2,543 votes.
Acharya said he told Zeliang about JD (U) legislator submitting letter of support to Rio on Sunday morning. "We will go with the NDPP", Sarma said in reply to a question.
While TR Zeliang had informed the Nagaland Governor of his decision to meet BJP leaders in Delhi, it was learnt earlier this morning that BJP leaders had refused to talk to him.
Stating that the resolution of the Naga political issue was the top priority of the NPF, party spokesperson Achumbemo Kikon told PTI, "In the interest of the peace process, the NPF had made a decision to reaffirm the alliance with the BJP and we want to continue the alliance".
The NDPP received a big boost when the Election Commission gave its nod to the returning officer of the 6-Tenning constituency to declare its candidate Namri Nchang as the victor, raising the final tally of the party to 18. Efforts of reporters to reach Zeliang were unsuccessful.