The announcement was made on the second day of the two-day meeting of the JDU state executive committee here.
Kushwaha has succeeded Rajya Sabha MP Vashishth Narayan Singh.
After being appointed as Bihar JDU chief Kushwaha said, "I will try to successfully fulfill my duty which I have received as State President. We will follow the basic mantra of our party, 'Development of all with justice."
"A lot of speculations about our party leader and CM Nitish Kumar are being made. We would like to clarify that our party stands strongly with NDA," he said.
The statement comes a day after the Bihar Chief Minister Nitish Kumar said that he could not understand who was his friend and who was his enemy before the state Assembly elections and hence the party suffered massive losses in the elections held in November 2019.
Kumar in a cryptic message to its ally, the Bharatiya Janata Party, had said, "We failed to anticipate who our friends were and were not, and on whom we should have trusted. After the election campaign, we got to understand that things were not conducive for us but by that time it was too late."
He had stated that the issue of his Cabinet expansion was not taken up for discussion during the talks he had with top BJP leaders at his official residence. By winning 74 seats against the JDU's tally of 43, the BJP is said to be insistent on having a bigger share of the pie. (ANI)