Putin was speaking through a video link at a summit of a Russia-led security bloc which was held in Tajikistan. He had planned to attend in person before the news of the virus outbreak in his inner circle this week.
It was previously unclear how big the outbreak was and how long Putin would remain isolated.
“This is not just one person or two people, there are dozens of people,” he said.
“And now I have to remain in self-isolation for a few days.”
Putin, 68, who has had two shots of Russia’s Sputnik V vaccine, said this week he was now personally testing its efficiency while the Kremlin said the president himself was healthy.
The Kremlin has had a rigorous regime in place designed to keep Putin away from anyone with COVID-19.
Kremlin visitors have had to pass through special disinfection tunnels, journalists attending his events must undergo multiple PCR tests, and some people he meets are asked to quarantine beforehand and be tested. (Reporting by Maxim Rodionov; Writing by Olzhas Auyezov; Editing by Toby Chopra and Raissa Kasolowsky)