Leaders of Russia, Germany and France will gather in Istanbul on Saturday to meet with Turkish President Recep Tayyip Erdogan on the agenda -- Syria. The quartet hopes to make some progress in finding a lasting solution for peace in the war-torn country. CGTN's Michal Bardavid has more.

Russian President Vladimir Putin, German Chancellor Angela Merkel and French President Emmanuel Macron are travelling to Istanbul for a summit hosted by their Turkish counterpart Recep Tayyip Erdogan.

IBRAHIM KALIN TURKISH PRESIDENTIAL SPOKESMAN "The quartet meeting will take place this Saturday October 27th under the leadership of our President Tayyip Erdogan. There, they will discuss issues such as Syria, the Idlib agreement, counter-terrorism, refugees and humanitarian aid."

Turkey and Russia have been cooperating closely on Syria. Last month, Ankara and Moscow brokered a deal on Idlib Province. The two agreed to create a 15-20 kilometer demilitarized zone and that heavy weapons would be pulled out of the region by October 15th. As the deadline passed, the two countries decided to allow more time for opposition groups to withdraw from de-escalation zones as some radical groups with links to al-Qaeda such as Hayat Tahrir al-Sham have shown resistance.

NAIM BABUROGLU ACADEMIC, ISTANBUL AYDIN UNIVERSITY "Even though the October 15th deadline has passed, Russia is sticking to the agreement because it believes Turkey is also doing so with good intentions in Idlib. So the cooperation between Turkey and Russia in Idlib is progressing positively."

The UN praised Turkey for its efforts to avert a humanitarian catastrophe in Idlib, where more than three million civilians remain. However, some experts say Russia may take some action if radical groups continue resisting.

NAIM BABUROGLU ACADEMIC, ISTANBUL AYDIN UNIVERSITY "If radical groups don't surrender their heavy weapons in the future. or harass Russia's air and military bases near Idlib -- such as the Hmeymim base-- then Russia could carry out target specific operations. Then Turkey would not block these operations."

In addition to Syria, other issues will be discussed at the Istanbul summit.

MICHAL BARDAVID ISTANBUL "One key topic, especially for Germany and France, is the prevention of a new refugee crisis. In 2016, Turkey signed a deal with the EU to stop the flow of refugees crossing from Turkey into European countries. Turkish officials say the number of attempts made by sea has dropped significantly."

The four leaders might also discuss the formation of a committee for the redrafting of Syria's constitution, a topic crucial to the political future of Syria. Michal Bardavid, CGTN, Istanbul.