Obama expressed optimism about the future of US-Russian collaboration in the ongoing Syrian conflict, suggesting Moscow might eventually shift its position on the fate of Syrian President Bashar al-Assad.

Nonetheless, Obama told reporters on Tuesday during a press conference at the UN climate summit in Paris that a change in Russia's position wouldn't happen overnight.

"I don't expect that you're going to see a 180-degree turn on their strategy over the next several weeks," the president said. "They have invested for years now in keeping Assad in power. Their presence there is predicated on propping him up. That's going to take some time for them to change how they think about the issue."

Future collaboration with Putin?

Still, Obama suggested that Russian President Vladimir Putin would eventually align itself with the US as it intensifies its war against the terrorist organization "Islamic State" (IS), which maintains a strong foothold in Syria.

"I think Mr. Putin understands that with Afghanistan fresh in the memory, for him to simply get bogged down in an inconclusive and paralyzing civil conflict is not the outcome that he's looking for," he said.

Assad has been the major figure of contention between world leaders seeking an end to the years-long conflict in Syria. Obama, Turkish President Recep Tayyip Erdogan and others want to see Assad removed; Putin wants to keep him in power.

Tension flared recently between Erdogan and Putin following the downing of a Russian jet along the border between Syria and Turkey. Obama urged both leaders to de-escalate tensions during the summit.

blc/jm (AP, Reuters, dpa)