Turkey's President Recep Tayyip Erdogan gestures as he addresses a meeting in Ankara, Turkey, Thursday, May 30, 2019. Erdogan and U.S. President Donald Trump will meet at next month's Group of 20 summit to discuss bilateral issues, including Ankara's plan to buy a Russian missile defense system that has raised the ire of the United States. (Presidential Press Service via AP, Pool)
Turkey's President Recep Tayyip Erdogan said the country has finalised a controversial deal to buy Russian S-400 missiles. AP

As Istanbul vote re-run approaches, Erdogan faces trouble within party