"Whatever decision we have taken will be in the interest of Bihar and its people. It will ensure development and justice. It will also ensure progress.
"This is a collective decision. I assure that our commitment is to the people of Bihar," Kumar told reporters after taking oath, amid reports that senior leaders like Sharad Yadav and party MP Ali Anwar were among those unhappy with his decision to align with the BJP.
Gandhi had alleged that Kumar had returned to "communal forces" for "selfish" political motives.
Kumar was today sworn in as the chief minister of the state. Senior BJP leader Sushil Kumar Modi, who will be his deputy in the new government, also took oath.
Kumar had resigned as chief minister of the Grand Allaince government last night after a fall out with the partner RJD over corruption charges against Lalu Yadav and some of his family members, including son Tejashwi, who was the deputy chief minister.