Russian and Turkish leaders will try to hammer out yet another deal to stabilise Idlib as tensions in Syria continue to rise.
An air strike on a rebel-held village in Syria has killed at least 15 people including children and injured several others, opposition activists said.
The activists blamed Russian warplanes for the strike on Maaret Musreen village, which is home to thousands of displaced people.
The Turkish president and his Russian counterpart are preparing to hold talks on Thursday, where Tayyip Erdogan will meet Vladimir Putin in Moscow.
On Sunday, Turkey confirmed it had launched a military operation against Russian-backed Syrian regime forces, following deadly clashes last month.
Doctor Wael Aleji from Syrian Christians for Peace told Premier: "It is very frustrating for Syrians because they feel abandoned. They feel used by everybody and nobody cares about what is happening in Syria.
"Nearly 700,000 Syrian civilians have been killed. Half of Syria's population are displaced; we are talking about nearly 7 million innocent people. Syrian people have suffered a lot. So we need to pray. We need to seek God and God's guidance and grace."
Russian air strikes have propelled a push by Syrian President Bashar al-Assad's forces to retake the last large rebel-held territory in the northwest.
That has sparked what the United Nations says may be the worst humanitarian crisis in a nine-year war that has driven millions from their homes and killed hundreds of thousands.
The Russian military has, however, repeatedly played down any talk of a refugee crisis and accused Turkey of violating international law by pouring enough troops into Idlib to make up a mechanised division.
Aleji called for Christians to pray ahead of the talks between Erdogan and Putin on Thursday that, "God would open the minds and hearts of all those involved in the war and that God would put on their [leaders] hearts to come together and negotiate an end to this to this war and an end to this suffering."