Talks to end Syria's civil war opened in Geneva Monday, but hopes for a breakthrough remained remote with the sides locked in a bitter dispute over the future of President Bashar al-Assad, AFP reports.

The negotiations, which began a day before the fifth anniversary of the outbreak of the conflict, are the latest effort to end violence that has killed more than 270,000 people and displaced millions.

As the delegations arrived in Geneva over the weekend, Damascus warned that any discussion about removing Assad would be a "red line".