India has the third-largest operating metro system in the world, after China and the United States. Replying to a supplementary question in the Rajya Sabha, Petroleum and Natural Gas Minister Hardeep Singh Puri stated that more than one thousand kilometres of metro rail is currently operational in 23 cities across the
country.
He further mentioned that 979 kilometres of metro lines are under construction, and upon completion, the metro network will extend to 29 cities. Mr Puri added that to become the second-largest urban metro network, the central government requires cooperation from state governments.