Those talks would be in addition to United Nations (UN) brokered talks that have been taking place intermittently in Geneva, Putin told reporters.

On Thursday, Syrian President Bashar al-Assad said the events taking place in the city of Aleppo are a historic moment, and said the world will be different after what he called the "liberation of Aleppo".

"What is happening today is the writing of a history written by every Syrian citizen. The writing did not start today, it started six years ago when the crisis and war started against Syria," Assad said in a video statement published on the Syrian Presidency's Twitter account.

Meanwhile, US Secretary of State John Kerry accused Syrian President Bashar al-Assad's government of carrying out "nothing short of a massacre" in Aleppo, where thousands on Thursday were evacuated under a ceasefire deal from the last rebel enclave in a city besieged by fighting for years.