"Prasad is making meaningless statements against the NDA government out of frustration and desperation," he told reporters in a reply to a question.
"He has lost credibility and slipped out of the heart and mind of the people of Bihar so much so that he will find it difficult to woo the masses for political revival," Kumar said.
On the RJD supremo's prediction of an imminent divorce between the JD(U) and BJP, he advised the former to worry about himself.
On Prasad's charge that the law and order situation has deteriorated in Bihar during the NDA rule and the minorities were being subjected to atrocities, Kumar said that contrary to the former's claims, both the masses and the minorities were satisfied with the law and order situation.
"The law and order situation in Bihar is under total control," the chief minister said adding steps have been taken to maintain law and order and conduct scientific investigation in criminal cases.
The police department has been equipped with devices and police personnel given training to maintain the law and order situation and investigate the criminal cases in a scientific manner, he said.