Russian President Vladimir Putin says he has discussed introducing de-escalation zones in Syria with Turkish President Recep Tayyip Erdogan during talks in Sochi on Wednesday and with US President Donald Trump in a phone call the previous day.

Consultations with Tehran and Damascus have also been held on the issue, Putin said.

"For the development of the political process [in Syria], a ceasefire must be provided... Russia, Turkey and Iran have all the time been thinking of how to secure this practice of a ceasefire. One of the methods is creating safe zones, or de-escalation zones," Putin said on Wednesday during a joint press conference with Turkish President Erdogan in Sochi.

Moscow has already conducted "preliminary consultations" with Damascus and Tehran on the matter, Putin said, adding that the issue has also been discussed with US President Trump, who appears to support the idea of safe zones.

"We all reason from [a position] that mechanisms to guarantee the end of bloodshed and provision for the beginning of a political dialogue must be created," the Russian president said, adding that Turkey also fully supports this position.

However, the different sides in the Syrian conflict should themselves make "the final decision," Putin added.

"In the end, only they are in charge of their country's fate. On our side, we – Russia, Turkey and Iran – as guarantors of a ceasefire, will make everything for such mechanisms to improve and be efficient," he told the media.

Moscow and Ankara both agree that "the creation of safe zones must lead to further conciliation and strengthening of the ceasefire regime" in war-torn Syria, Putin said.

The Russian president pointed out that regardless of safe zones, the fight will continue against terrorist organizations in Syria such as Islamic State (IS, formerly ISIS/ISIL), Al-Nusra Front and other groups seen as terrorist by the United Nations.

The question of ceasefire monitoring in possible de-escalation zones is "an issue for separate talks," Putin added, saying that international military officials are in contact on the subject.

"In terms of air force flights, aviation will also not be deployed in de-escalation zones, on condition of no military activity there," the Russian president told journalists in Sochi.

The Turkish leader said that while he and the Russian president had discussed the issue of safe zones in Syria during their Sochi negotiations, it is the Astana peace talks participants who will work on the question. "I hope that a de-escalation zone will be implemented," Erdogan said.

The topic of de-escalation zones is especially related to the province of Idlib, where "many people from Aleppo have found refuge," the Turkish president pointed out.

Having reiterated calls to stop the bloodshed of innocent people in Syria, the Turkish president said that both Moscow and Ankara back punishment for those behind an alleged chemical attack in the town of Khan Shaykhun in Syria's Idlib province.

"Such a barbaric attack must not be left unpunished," Erdogan said.