ST PETERSBURG (AFP) - Russian President Vladimir Putin on Friday said he held talks on Syria with US President Barack Obama on the sidelines of the G20 summit but confirmed the meeting did not end their differences on the conflict.

"We spoke sitting down... it was a constructive, meaningful, cordial conversation. Each of us kept with our own opinion," Mr Putin told reporters, saying the meeting lasted 20 to 30 minutes.

"There is dialogue, we hear each other and understand the arguments," he said. "He (Obama) disagrees with my arguments, I disagree with his arguments, but we do hear, and we try to analyse," he said.

His chief foreign policy aide Yury Ushakov also confirmed that the "contradictions remained" after the talks.

Mr Putin said that a majority of countries at the G20 appeared to be supporting his position.

"You said views divided 50-50, that is not quite right," Mr Putin said in answer to a journalist's question, listing only the United States, Turkey, Canada, Saudi Arabia and France as countries supporting an intervention.

He said German Chancellor Angela Merkel remained "careful" and that while the British Prime Minister David Cameron supports the strike, he does not represent the "will of the people" as parliament rejected intervention.

Meanwhile, China, India, Indonesia, Argentina, Brazil, South Africa, Italy were "against military action," he said.

Even in the countries supporting the strikes, "the majority of the population is on our side," opposing them, he added.

"Using force against a sovereign state can only be done in self defence, and Syria is not attacking the United States," said Mr Putin, adding such action could only be approved by the UN Security Council.

"As one participant said yesterday, those who do something different are placing themselves outside the law."