REUTERS

Clapper said Putin was "very impulsive and opportunistic" as he increased Russian support for close ally President Bashar al-Assad in Syria's roiling civil war, CNN reported.

"I personally question whether he has some long-term strategy or whether he is being very opportunistic on a day-to-day basis," Clapper told CNN's Jim Sciutto. "And I think his intervention into Syria is another manifestation of that."

When asked if Putin had a plan for Syria, Clapper said Putin didn't.

"What his long term plan is, I'm not sure he has one," Clapper said. "I think he is kind of winging this day to day."

Read alsoIran to be invited to key Syria talks, U.S. says: mediaClapper's comments come as Secretary of State John Kerry is scheduled to meet with Russian officials in Vienna Friday as part of international talks on a Syrian peace deal.

Read alsoSaudi participation in Syria talks aims to test Russia, IranU.S. officials have in the past called Russia's airstrikes a "strategic blunder," with President Barack Obama saying earlier this month that Russia was heading for a "quagmire" in the country.

"It just won't work, and they're going to stay there for a while," Obama said at a news conference.