Speaking to a TV news channel, he said, "Well, I hope it will happen."
He was responding a question when asked if he thinks that the US should try to press the issue and have India brought into the system as a nuclear weapons state.
When asked if it is fair to say that one of the ultimate objectives of India would perhaps be to become a member of the Non-Proliferation Treaty system, Singh said, "It would be a positive development."
"We are a nuclear weapons state, but we are a responsible nuclear power. We have an impeccable record of not having contributed to unauthorised proliferation of these weapons of mass destruction," he added.