U.S. Secretary of State John Kerry will visit Turkey in late August, broadcaster CNN Turk said on Thursday, more than a month after a failed military coup shook the NATO member state. Turkey's relations with Washington have been strained by the abortive putsch, which President Tayyip Erdogan blames on U.S.-based Turkish cleric Fethullah Gulen. Erdogan has called for the extradition of Gulen, who denies involvement in the plot.