Turkey's President Recep Tayyip Erdoğan on Wednesday attended the opening of the Moscow Mosque with Russian President Vladimir Putin and Palestinian National Authority President Mahmoud Abbas. Erdoğan and Putin held a meeting following the opening ceremony and discussed Russia's increasing military presence in Syria and its support for Bashar Assad's regime in Damascus, which continues to stand as the major thorn in Turkish-Russian relations. Erdoğan reportedly argued with Putin once again that the Assad regime is the main source of instability in the region and will underline that Russia and Iran's peace initiatives are unlikely to bring peace for as long as Assad remains in power. Interim Foreign Minister Feridun Sinirlioğlu recently visited Russia and discussed Ankara's concerns over Moscow's alleged plan to create a military base in Syria's Latakia.Harshly criticizing Russian interference in Syria, Erdoğan has recently said it is unconscientious to look at the situation from a point of view focused on international balance of power and political calculations. He called upon the international community once again to take immediate action and take steps to resolve the crisis in Syria by bringing down the oppressive regime in the country and replace it with a democratic administration. "Otherwise, it is evident that people will continue to move out of Syria to seek refuge if the conflict is not stopped," he underscored. Millions of people have been forced to flee as a result of turmoil in the Middle East and the five-year war in Syria. According to U.N. figures, Turkey officially hosts 1.8 million refugees, while Turkish officials claim the figure is over 2 million.