New Delhi, June 5 -- President Vladimir Putin said Thursday that Russia will strengthen its air defenses to counter recent Ukrainian drone attacks, which have reached deep inside his country and cast a cloud over his showcase economic forum in his hometown of St. Petersburg.

Speaking in response to a question from The Associated Press during a meeting with heads of international news agencies, Putin acknowledged the damage from Ukrainian drone attacks.

"To our regret, some of them break through," Putin said of the drone strikes. "Russia has an air defense system, we need to improve it, strengthen it, and we will do that."

The wide-ranging media session came on the sidelines of the St. Petersburg International Economic Forum, his annual...