Despite Turkey's recent release of American priest Andrew Branson, after two years of detention, this issue will not only derail the obstacles to normalization of relations between Washington and Ankara.
Ankara is still demanding that Washington extradite US-born cleric Fathullah Gulen, who has been accused by Turkey of being behind the failed coup in July 2016.
The Gulen case is the biggest obstacle to the return of relations between Turkey and the United States according to analysts, as the latter insists on its position not to respond to repeated Turkish demands to hand over to Ankara.
The second obstacle is to protect the Kurdish people, which operate in northern Syria on the border with Turkey, and have played a major role in expelling an organization calling for the terrorist from there with American support.
US support for these units has angered Turkey, considering it an extension of the outlawed Kurdistan Workers' Party (PKK) in Turkey.
The case of Turkish banker Mohammed Hakan Attila, a detainee in the United States, for violating sanctions against Iran, is the third obstacle to relations between the two countries in months.
In January, a US court charged Attila with five counts, including bank fraud, deception of US banks and involvement in money laundering, which Ankara strongly criticized.
The fourth obstacle was the announcement of Moscow, about two months ago, that it will begin delivery of advanced S-400 missile defense system to Ankara next year, which increased tension between Turkey and the United States.
Washington has expressed concern about the deployment of Turkey, a member of the North Atlantic Treaty Organization (NATO), the Russian-made S-400 missiles, which could pose a threat to a number of US-made weapons used in Turkey, including the F-35.
The fifth outstanding issue between the two countries is the return of US Ambassador John Pass to Ankara, after leaving the country about a year ago amid strained relations between Ankara and Washington on a number of regional and international files.
