An operation to evacuate civilians and fighters from the last rebel-held parts of Aleppo was suspended on Friday, a Syrian security source said, accusing the opposition of violating the deal.

"The evacuation operation has been suspended because the militants failed to respect the conditions of the agreement," the security source told AFP.

"The next step (after Aleppo) will be to reach agreement on a complete ceasefire across all of Syria," Putin had said on an official visit to Japan.