UN Secretary-General Ban Ki-moon said Tuesday that Syria's descent into war could have been avoided if regional powers had not used the conflict as a battlefield to settle scores, AFP reports.

In a statement marking five years since the start of the war, Ban warned that if peace talks fail, "the consequences for the Syrian people and the world are too frightening to contemplate."

The conflict in Syria began as street protests calling for political change that were met with repression, but the destruction that engulfed Syria "was not inevitable," Ban said.

The Syrian government could have responded peacefully to calls for change but regional powers are also to blame for fueling the war, he said.

"Regional and international actors could have united to help Syria stabilize rather than use it as a battlefield for regional rivalries and geo-strategic competition," he said.