<span style="color: #222222;">A top UN official in India has welcomed Prime Minister Narendra Modi's decision of a 21-day nationwide lockdown to contain the spread of the deadly novel coronavirus, saying collective efforts are required to overcome one of the greatest health threats of our lifetime. <br />''<br />''Mr Modi on Tuesday announced a nationwide lockdown for three weeks in an attempt to stem the spread of coronavirus in India.<br />''<br />''Spokesman for the UN Secretary-General Stephane Dujarric said that UN Resident Coordinator in India Renata Dessallien welcomed Prime Minister Modi's strategy for a nationwide 21-day lockdown to curtail the spread of the virus.</span><br />