Janata Dal-United (JD-U) leader Nitish Kumar will remain the chief minister of Bihar, RJD leader Lalu Prasad said on Sunday, after the Grand Alliance trounced the BJP in assembly elections.

Addressing the media at the Rashtriya Janata Dal (RJD) headquarters here, Lalu Prasad also said that his party and the JD-U will build a campaign against Prime Minister Narendra Modi nationwide.

Hailing Nitish Kumar's leadership, Lalu Prasad said: "I congratulate Nitish Kumar. Nitish Kumar will run the government."

He said Bihar will develop in a major way under Nitish Kumar's leadership.

"The people of Bihar have wiped out the BJP, chased out the BJP," Lalu Prasad thundered, adding that the BJP combine's defeat would have a major impact on national politics.

He said he would also go to Varanasi in neighbouring Uttar Pradesh to see if Modi had fulfilled his election promises in his Lok Sabha constituency.

The RJD emerged as the single largest party in the 243-member Bihar assembly after contesting the assembly elections in alliance with the JD-U. Both parties contested 101 seats.

The Congress, the third ally, put up candidates in 41 places.