US frigate USS Taylor passes through the Bosphorus strait on its way to Black Sea in Istanbul on April 22, 2014. The US frigate USS Taylor passed through Istanbul's Bosphorus Strait on Tuesday and sailed back to the Black Sea. (Xinhua/Lu Zhe)

US frigate USS Taylor passes through the Bosphorus strait on its way to Black Sea in Istanbul on April 22, 2014. The US frigate USS Taylor passed through Istanbul's Bosphorus Strait on Tuesday and sailed back to the Black Sea. (Xinhua/Lu Zhe)

US frigate USS Taylor passes through the Bosphorus strait on its way to Black Sea in Istanbul on April 22, 2014. The US frigate USS Taylor passed through Istanbul's Bosphorus Strait on Tuesday and sailed back to the Black Sea. (Xinhua/Lu Zhe)

US frigate USS Taylor passes through the Bosphorus strait on its way to Black Sea in Istanbul on April 22, 2014. The US frigate USS Taylor passed through Istanbul's Bosphorus Strait on Tuesday and sailed back to the Black Sea. (Xinhua/Lu Zhe)

US frigate USS Taylor passes through the Bosphorus strait on its way to Black Sea in Istanbul on April 22, 2014. The US frigate USS Taylor passed through Istanbul's Bosphorus Strait on Tuesday and sailed back to the Black Sea. (Xinhua/Lu Zhe)