Obama and Putin hold ’candid, blunt and businesslike’ talks
The body language suggested anything but friendship.
Yet Barack Obama and Vladimir Putin both claimed to have had firm and productive talks about ending the civil war in Syria and focussing their military assets against Isis.
Mr Putin even claimed a deal could be reached within days.
The US and Russia are on opposing sides of a five-year conflict that has killed 500,000 people, and displaced up to 12 million.
Russia is acting to support the continued rule of President Bashar Al-Assad, while the US is supporting and arming rebels dedicated to his overthrow.
Speaking in China where he attended his final G20 summit, Mr Obama said that he had spoken with Mr Putin for 90 minutes and raised with him the humanitarian situation in the country.
He said his talks had been "candid, blunt and businesslike".
"We had some productive talks about what a cessation of hostilities would look like for Russia and the US to focus on our common enemies," he said.
"But given the gap of trust that exists, that is a tough negotiation and we have not closed the gap yet."
Secretary of State John Kerry and Russian foreign minister Sergey Lavrov have for weeks been trying to broker a deal that would curb the violence between the Mr Assad's government forces and rebels backed by the US.
The deal depends on the two sides agreeing to closer military co-ordination against extremist groups operating in Syria, something the Russians have long sought and the US resisted.
Mr Obama did not detail the trouble spots, although he suggested the US has concerns about Russia holding up its end of the bargain and enforcing the terms.
Any deal would depend on Moscow using its influence to persuade the Syrian leader to ground planes and stop the assault on opposition forces, the Associated Press said.
Mr Obama said the aim was to reach "meaningful, serious, verifiable cessations of hostilities in Syria".
Mr Obama's meeting with Mr Putin came as the Russia leader is at the centre of controversy surrounding the US presidential election.
US officials blame Russian intelligence for a hack on the Democratic National Committee that resulted in a leak of emails damaging to its presidential nominee, Hillary Clinton.
Mr Putin has denied his government was involved, but cheered the release of the information. On Monday, it was reported that US intelligence agencies are probing what they believe are Russian efforts to influence the vote.
Reuters said that Mr Putin said on Monday that an agreement with the US on finding a way to significantly reduce the death toll in Syria could be reached in the next few days.
Speaking to reporters in the Chinese city of Hangzhou, he said it was premature to give details about the terms of the agreement, but that Russia would strengthen co-operation with the United States on fighting terrorism.
Mr Obama and Mr Putin also discussed the conflict in Ukraine, where Russian-backed separatists have been fighting the government, and the implementation of the agreement to stop the violence.
Mr Obama met earlier with French President Francois Hollande and German Chancellor Angela Merkel on the same issue.