The remains of an Israel F-16 fighter jet in Harduf (Photo: AFP)

UN spokesman Stephane Dujarric said in a statement that Guterres is following closely the alarming military escalation throughout Syria and the dangerous spillover across its borders.

On Saturday, Israel conducted airstrikes against Iranian facilities in Syria, claiming an Iranian drone had entered the Israeli airspace from Syria. Israel said the Syrian missiles shot down an F-16 fighter jet of the Israeli Air Force. The incident was the most serious confrontation between Iran and Israel since Syria's war began in 2011.