German Chancellor Angela Merkel, Russian President Vladimir Putin and French President Emmanuel Macron (R-L) at G20 summit, Hamburg, Germany, July 8, 2017 (Tobias Schwarz/Reuters)

The leaders of Turkey, Russia, France, and Germany will discuss the Syrian conflict in Istanbul on October 27.

Officials said Emmanuel Macron and Angela Merkel will join Turkish and Russian Presidents Recep Tayyip Erdoğan and Vladimir Putin, who agreed a demilitarized zone for opposition-held northwest Syria last month.

The agreement suspended a Russian-regime offensive to reoccupy the last major opposition area in the 91-month Syrian conflict. It has held up despite the Assad regime’s vow to regain “every inch” of the country, including territory held by Kurdish groups in north and east Syria.

Earlier this week, as a deadline for withdrawal of “radical” factions passed, Russia accepted the ongoing presence of rebel fighters and even the jihadist bloc Hay’at Tahrir al-Sham in the 15 to 20-km wide and 100-km long zone around Idlib and northern Hama Provinces.

Rebels withdrew their heavy weapons, as Turkish troops moved in arms to oversee the ceasefire.

An estimated three million people, more than half of them displaced from other areas of Syria, live in the area.

French President Macron’s office said on Friday that it wants to prevent another humanitarian disaster and flow of refugees.

“We want to keep this stability and work from this agreement to move into a new phase of discussions on a political process,” said a senior French diplomatic source. “And that it helps launch this constitutional committee that the UN is working on so that it meets as quickly as possible.”

A spokeswoman for the German government said Chancellor Angela Merkel will focus on support of the de-escalation zone.

“The Federal Government sees Russia, as an ally of the Assad regime, as a partner with a very particular responsibility,” the spokeswoman said.