"I will support the party in all its decisions (on the selection of its prime ministerial candidate)," the animal rights activist told newsmen.
She was here in connection with a programme on cow protection.
Asked on JD(U)'s reservation on Modi, Gandhi said it was that party's view and BJP should work hard to strengthen itself.
Recently senior party leader Yashwant Sinha had triggered a debate in NDA after he said most party workers desired Modi to be BJP's prime ministerial candidate for the 2014 general elections.