Rashtriya Janata Dal chief Lalu Prasad Yadav met Congress party President Sonia Gandhi in New Delhi on Thursday.
The meeting was held as Lalu made an attempt to form an RJD-led government in Bihar.
After the 30-minute meeting at Gandhi's residence, Lalu left without addressing the media.
He later met his supporters.
On Wednesday, the Congress pledged support to the RJD, to Bihar Governor Buta Singh.
In the numbers game, the Congress-RJD combine stands at 84, 38 short of a majority in the 243-member assembly.
Earlier reports:
Bihar: Rabri may stake claim today
Buta may do a Jharkhand in Bihar
Cong supports RJD bid in Bihar