With Bihar Assembly elections scheduled for later this year, JD(U) and RJD are also likely to finalise their seat-sharing agreement which has faced some hurdles over the share of the two parties.
Kumar held a meeting with JD(U) president Sharad Yadav over the issue.
Prasad had also said in a tweet that he will meet Yadav, who has been named as the head of the new outfit, "for finalisiation of merger modalities".
The ruling parties in UP and Bihar, Samajwadi Party and JD(U), RJD, INLD, JD(S) and Samajwadi Janata Party had formally decided to merge at a meeting at the residence of the SP President.
The merger came almost two decades after the then Janata Dal disintegrated in the 90s.
