Russia, one of the Syrian government’s staunchest allies, and Turkey brokered a deal in September to create a demilitarized zone in the northwest Idlib region that would be free of all heavy weapons and jihadist fighters.
The deal helped avert a government assault on the region, the last major bastion of opponents of President Bashar al-Assad.
But Moscow has since complained about escalating violence in the area and said that militants who used to belong to the Nusra Front group are in control of large swaths of territory.
Speaking in Beijing, Putin said that Moscow and Damascus would continue what he called the fight against terrorism and that any militants who tried to break out of Idlib, something he said happened from time to time, were bombed.
But Putin said the presence of civilians in parts of Idlib where militants were also active meant the time was not yet ripe for full-scale military operations.
"I don't rule it (a full-scale assault) out, but right now we and our Syrian friends consider that to be inadvisable given this humanitarian element," Putin told reporters.
Moscow is keen to help Assad retake territory, including eventually Idlib province, but Turkish President Tayyip Erdogan has argued against a Russian-backed offensive in a region that borders his own country.Ankara is concerned about potential refugee flows from Idlib in the event of a military operation, and wants to retain its influence there.