Lauding India for its role in eliminating two 'silent killers' -- smallpox and polio, the World Health Organization (WHO) has backed the country to take aggressive action against the global pandemic coronavirus or COVID-19 that has claimed over 16,000 lives across the world so far.

Speaking at a press conference on Monday, Michael J. Ryan, WHO Executive Director said the future of this pandemic will largely depend on what densely populated countries like India and China do to tackle this unprecedented health crisis.

"India is a hugely populous country. The future of this pandemic to a great extent will be determined to what happens to densely populated countries. It's really important that India continues to take aggressive action at the public health level, and at the level of society to control, suppress this disease and save lives," Ryan said.

"India led the world in eradicating two silent killers -- small pox... India, through targeted public health interaction, ended that disease and gave a great gift to the world... India also eliminated polio, another silent killer and did a tremendous job. India has tremendous capacities," he said.

Ryan's remarks assume significance as they have come at a time when India imposed strict lockdown measures to curb the spread of coronavirus.

Thirty states and union territories announced complete lockdown in their entire areas covering as many as 548 districts, the government said on Monday. The unprecedented decision was taken in the wake of the outbreak of the deadly coronavirus.

The 30 states imposing complete lockdown include capital Delhi, Maharashtra, Bihar, Tripura, Assam, West Bengal, Rajasthan, Jammu & Kashmir, Ladakh, Punjab, Gujarat, Karnataka among others.

Apart from the 30 states or UTs facing complete lockdown, three states or UTs have imposed partial lockdown in certain areas. Total 58 districts will be affected due to this. They are Uttar Pradesh -- India's most populous state, Madhya Pradesh and Odisha. Moreover, another union territory -- Lakshwadweep has imposed closure of some activities in its area.

So far, Sikkim and Mizoram are the only two states who haven't imposed any restrictions.

The total number of confirmed Covid-19 cases in India stands at 415, according to the Indian Council of Medical Research (ICMR). Nine people have succumbed to the virus till now.