"The issue was discussed," spokesman Dmitry Peskov was quoted by Russian agencies as saying in response to the question of who initiated the proposal that Syria hand over its chemical arsenal in order to avert a US strike.
But Peskov did not say who first mooted the idea. "We're not disclosing the contents of the conversation," he said.
Despite having no bilateral talks scheduled, Putin and Obama had a half-hour discussion on the sidelines of the two-day Group of 20 summit Putin hosted last week, with the conversation focused heavily on Syria.
Obama confirmed in an interview Monday with PBS Newshour that he "had conversations" with Putin in Saint Petersburg about the plan for Syria's chemical arms, announced by Russian Foreign Minister Sergei Lavrov just hours earlier.
"And this is a continuation of conversations I've had with President Putin for quite some time," Obama said in the interview.
Foreign Minister Sergei Lavrov also indicated Tuesday that the plan was born out of joint US-Russia efforts to iron out their disagreements over handling of the Syrian conflict.
"The proposal to place Syria's chemical arms under international control is not entirely a Russian initiative," Lavrov said.
"It has emerged from the contacts we had with American colleagues, from yesterday's statement by John Kerry, who allowed for the possibility to avoid strikes if this problem can be solved."