Obama and Putin are scheduled to talk on Monday after Putin addresses the United Nations.
Russia has no plans for now to deploy combat troops in Syria, President Vladimir Putin said on Sunday, addressing US concerns about a Russian military build-up.
In an interview with US television networks recorded ahead of a meeting with US President Barack Obama, Putin said the aim of Russia's military presence in Syria was to support the government of President Bashar al-Assad against terrorist groups.
"Russia will not take part in any field operations on the territory of Syria or in other states; at least, we do not plan it for now," he said in a transcript of the interview with US television networks CBS and PBS released by the Kremlin.
Obama and Putin are scheduled to talk on Monday after Putin addresses the United Nations, although White House and Kremlin officials have disagreed on what the two leaders will discuss and even who initiated the meeting.
Russia has stepped up its military involvement in Syria in recent weeks, with US officials accusing Moscow of sending combat aircraft, tanks and other equipment to help the Syrian army. The sudden military build-up in support of Assad and a refugee crisis that has spilled over from the region into Europe have lent urgency to attempts to resolve the Syria conflict.
U.S.-Russian relations have slumped to a post-Cold War low over the Ukraine crisis, although the two sides shares concerns about the threat posed by Islamic State while disagreeing on the approach.
Moscow says Damascus should be included in international efforts to fight Islamic State, a demand the United States and other Western powers reject.
"There is no other way to settle the Syrian conflict other than by strengthening the existing legitimate government agencies, support them in their fight against terrorism," Putin said. "There are more than 2,000 militants in Syria from the former Soviet Union," he added. "Instead of waiting for them to return back home we should help President al-Assad fight them there, in Syria."
In an excerpt from the interview released earlier on Sunday, Putin branded US support for rebel forces who oppose Assad as illegal and ineffective, saying US-trained fighters were leaving to join Islamic State with weapons supplied by Washington.
Critics have urged Obama to be more decisive in the Middle East and Syria, where the United Nations has said 250,000 people have died after four years of conflict, and say lack of a clear American policy has given Islamic State opportunities to expand.