Rising anti-American sentiment in Turkey has occurred since the start of the Turkish invasion of northern Syria in January 2018 aimed at ousting Syrian Kurdish forces from the enclave of Afrin. A poll conducted in Turkey during the operation revealed that 90 percent of respondents believed that the United States is "behind" the Kurdish PKK and YPG. After the start of the Turkish invasion, U.S. Secretary of Defense Jim Mattis stated that "Turkey is a NATO ally. It's the only NATO country with an active insurgency inside its borders. And Turkey has legitimate security concerns." Turkish Deputy Prime Minister Bekir Bozdag urged the United States to halt its support for Kurdish YPG fighters, saying: "Those who support the terrorist organization will become a target in this battle."