Kumar also said that it would be "good" if regional parties like JD(U), Trinamool Congress and BJD form a common front.
Kumar said, "L K Advani discussed some issues and said some things. We will discuss them in our meeting. We will take cognisance of these things...We will discuss all issues," he told reporters in Patna.
"Before that it is not proper for me to say anything. But we are concerned about the developments which have taken place in the last few days," Kumar said amidst rumblings in NDA over Narendra Modi's appointment as BJP's election campaign committee chief.
Kumar, who is also in touch with Odisha Chief Minister Naveen Patnaik, said, "If all of us together understand these problems and form a common front it would be good...This is at an initial stage and one should not speculate that a political front has been formed."
Sources, however, said there was "no positive indication" from the meeting during which Yadav mainly apprised BJP leaders about JD(U)'s concerns.
BJP President Rajnath Singh called up the Bihar Chief Minister today morning while senior BJP leader Murli Manohar Joshi talked to Kumar last night.