Jairam Ramesh told a meeting in New Delhi on Thursday that India, where 130 million households are without a latrine, accounted for 60 per cent of the global volume of open defecation.
"This is a matter of great shame, anguish, sorrow, and actually anger," Mr Ramesh, who is also responsible for the Ministry of Drinking Water and Sanitation, was quoted as saying by the Times of India.
He unveiled a proposal to spend 1.5 billion rupees ($28 million) to provide 100,000 bio-toilets to villages across India in the next two years.
He also proposed a 5.0 billion rupee project to replace the open-hole toilets on the 50,000 coaches that ply India's vast railway network with bio-toilets over the next five years.
Carrying 11 million passengers a day, Indian Railways "is really the largest open toilet in the world", Mr Ramesh said, adding that his ministry would be willing to pick up half the cost of the toilet re-fit.