Passport expiry for travelling to USA


My child is in India and the passport is getting expired in the end of this year but L2 visa is valid till 2016. Could you please suggest me with the answers for the following questions

  1. Can my child travel to USA with less than 6 months passport validity. If yes what is the minimum validity required to enter into USA.

  2. Can we apply for renewal of passport in USA and what is the minimum validity required for the renewal application.

  3. We both the parents are in USA, Please suggest me which one is the better way to get my child’s passport renewal, applying in India or applying in USA.