Sputnik V is the third drug to be approved by India after Oxford-AstraZeneca's Covishield and Covaxin, which was developed by Indian firm Bharat Biotech.
The country of more than 80 million has lost more than 61,000 lives out of over 1.7 million cases of Covid-19 infection, according to health ministry figures.
The coronavirus pandemic is showing no signs of slowing down, with infections surging past 94 million and more than two million deaths, and Europe among the hardest-hit parts of the world.
Sagasti said no direct flights from the United Kingdom had entered the country since December 15, when flights from Europe restarted. But health authorities were monitoring passengers from Britain who had entered through connecting flights, he said.