TEHRAN — Faisal Mekdad, the Syrian Foreign Minister, arrived in Tehran late on Tuesday to be briefed about the latest decisions following the meeting of the presidents of Iran, Russia and Turkey on Tuesday to assess the situation in Syria within the Astana format. During the trilateral summit, Iranian President Ebrahim Raisi said, “The international community bears the responsibility to solve the crisis of the displaced and Syrian refugees, and we will support any initiative to do so.”He then noted that Syria’s sovereignty is a red line and the illegal presence of the United States there is the “cause of instability.”For his part, Russia’s Putin said that thanks to cooperation through the Astana process, the level of violence in Syria has decreased and there is now a political process.