Ahead of peace talks, rebels' representative says it's a 'real test of the power of Russia' to hold off Iran and the Syrian government.
Putin said the Syrian government and opposition have signed a number of documents.
The battle of Aleppo, one of the worst of a civil war that has drawn in global and regional powers, has ended with victory for Syrian President Bashar al-Assad.
The Syrian army have made rapid gains against insurgents in the past two weeks and look closer than ever to restoring full control over Aleppo.
Putin's spokesman said militants are using the truce to regroup, rearm and attack.
Syrian army attacks rebel-held areas in Aleppo hours after ceasefire deal is announced.
Moscow also blamed al-Nusra for hostilities in three provinces.
Both France and Russia have said that peace talks in Geneva must continue.
A U.S.-Russia brokered cessation of hostilities has been in place since Saturday.