He praised Prime Minister Modi, calling him the "biggest leader" in the country and added that "there is no one who can defeat him."
Interestingly, Nitish Kumar had taken a morally high ground in June 2013 when he broke his 17-year tie with the Bharatiya Janata Party (BJP) over the naming of Narendra Modi as its prime ministerial candidate for the 2014 Lok Sabha elections.
Since then, he was claiming that he will never join hands with BJP again, until July 26 when he resigned as the chief minister and ended two-year alliance with the RJD and the Congress over corruption charges against his deputy and Lalu Prasad's son Tejashwi Yadav and formed the Government in Bihar very next day with the BJP's support.
Earlier in July 2015, Prime Minister Modi had also attacked Nitish over his frequent change of political allegiances, saying it seemed that there was "some problem with Nitish Kumar's DNA".
Speaking in his first press conference after snapping ties with long time ally Rashtriya Janata Dal (RJD), Nitish today also explained that he had given Lalu Yadav ample opportunities to explain the charges of corruption against him, but to no avail.
If Lalu had explained himself over the corruption allegations, then situation could have been different in Bihar, Nitish said.
"I had asked Lalu to clarify the allegations of corruption against him and put the facts forward. It will send a positive impact on the public and which is also good for 'mahagathbandhan. I have tolerated everything, thought this happens in alliance as I didn't have a choice. I continued my work for the betterment of people," he added.
Meanwhile, Lalu has invited the Janata Dal (United) co-founder Sharad Yadav to lead the fight against the BJP and Nitish , who, according to him, joined hands with "communal and fascist forces and betrayed the people's mandate".
"Nitish has tarnished the image of Ambedkar. I urge Sharad Yadav, whom we consider the true leader, to travel to every corner of the country and come to Bihar and join our fight against the BJP and Nitish Kumar," Lalu told ANI.
On July 26, Nitish resigned as the chief minister and ended two-year alliance with the RJD and the Congress over corruption charges against his deputy and Prasad's son Tejashwi Yadav.