How to avoid getting “sudo: Account or password is expired, reset your password and try again”

I am trying to add user e.g. amit to group amit,as below.

root# groupadd -g 1500 -f amit                              
root# useradd amit -m -G sudo -u 1500 -g 1500 -o -p "amit"

However, when I try to switch to user amit it gives out the message as below:

root# sudo su - amit
sudo: Account or password is expired, reset your password and try again
Changing password for root.

May I please know, why am I getting this message, what should I do in order to avoid getting this message and get directly switched to amit user.