Amid rising Covid cases linked to Omicron, Prime Minister Narendra Modi on Sunday said individual alertness and discipline are a big strength of the country in the fight against the new variant of coronavirus.

In his Mann Ki Baat radio broadcast, Modi said India has achieved "unprecedented feat" in its inoculation drive but cautioned against the new variant of the virus.

"This new Omicron variant is being constantly reviewed by our scientists. Every day they are getting new data and steps are being taken based on their suggestions," Modi said.

Individual alertness and discipline are a "big strength" of the country in the fight against the new variant of coronavirus, he said.

"It is our collective strength which will defeat corona. We have to enter 2022 with this sense of responsibility," the prime minister said.

Modi on Saturday had announced that vaccination against COVID-19 for children between 15 and 18 years will start from January 3, while "precaution dose" for healthcare and frontline workers would be administered from January 10.

He had also said the precaution dose will also be available for citizens above 60 years of age and those with comorbidities on the advice of their doctor from January 10 next year.

In his Mann Ki Baat address on Sunday, Modi also talked about Group Captain Varun Singh, who succumbed to injuries at a military hospital in Bengaluru last week after sustaining serious injuries in the chopper crash near Coonoor that killed CDS Gen Bipin Rawat, his wife and 11 armed forces personnel.

Group Captain Singh was the lone survivor of the December 8 crash.

The prime minister talked about the air warrior's inspiring letter to his school weeks after he was decorated with the Shaurya Chakra award for displaying exemplary composure and skill.