"The Politburo calls upon Central government to provide all required assistance and activate National Disaster Management Authority to undertake relief and rehabilitation operations on a war footing.
"It calls upon the Central government to take long-term measures including de-silting of Ganga which every year is causing floods and consequent damage," it said in a statement.
The party also asked Nitish Kumar government in the state to organise provision of immediate relief and adequate compensation for those who have lost "virtually everything".
According to the state disaster management department, the inundation has affected around 31.33 lakh people in 1,934 villages in 12 districts.