Factbox: Turkey's Russian missile deal strains ties with Washington

FILE PHOTO: U.S. President Donald Trump shakes hands during a bilateral meeting with Turkey's President Tayyip Erdogan during the G20 leaders summit in Osaka, Japan, June 29, 2019. REUTERS/Kevin Lamarque/File Photo

ISTANBUL (Reuters) - Russia started delivering advanced missile defence equipment to NATO member Turkey on Friday, the Defence Ministry in Ankara said, setting the stage for likely U.S. sanctions on Ankara.

The dispute over the S-400 air defence missiles, which the United States says are incompatible with NATO military systems and could threaten U.S. F-35 stealth fighter jets which Turkey has also ordered, is one of several issues which have frayed ties between the two allies.