Indias Prime Minister Narendra Modi is displayed on screens in an electronics store during his address to the nation in New Delhi, India, on Thursday, March 19, 2020.

India will begin the world's largest lockdown, Prime Minister Narendra Modi announced in a TV address Tuesday night, warning that anyone going outside risked inviting the coronavirus inside their homes, and pledging $2 billion to bolster the country's beleaguered health care system.

"To save India and every Indian, there will be a total ban on venturing out of your homes," Modi said, adding that if the country failed to manage the next 21 days, it could be set back by 21 years.

India's stay-at-home order puts nearly one-fifth of the world's population under lockdown.

Indian health officials have reported 469 active cases of COVID-19, the disease caused by the virus, and 10 deaths. Officials have repeatedly insisted there is no evidence yet of communal spread but have conducted relatively scant testing for the disease.

In recent days, India has been gradually expanding stay-at-home orders and has banned international and domestic flights and suspended passenger service on its extensive rail system.

Essential service providers, including hospitals, police and media had been exempted from the stay-in-place orders, and many grocery stores and pharmacies remained open.

Modi called Tuesday's order a "total lockdown" and did not address whether any service providers would be exempt, but said that "all steps have been taken by central and state government to ensure supply of essential items."