President Vladimir Putin has told world leaders at the G20 summit in Russia that a return to economic crisis cannot be ruled out.
He said on Thursday they had not resolved the problem of returning the world economy towards steady and balanced growth.
The BBC reports the G20 meeting in St Petersburg made progress on tightening multinational company tax avoidance.
But the meeting's economic agenda is overshadowed by the Syrian crisis.
"Our main task is returning the global economy towards steady and balanced growth. This task has unfortunately not been resolved,'' said Mr Putin.
"Systemic risks, the conditions for an acute crisis relapse, persist."