China had protested what it called "close-in reconnaissance" of Chinese territory by the U.S. military in the past.

"China has even in the past put out maps which claim the territories which ... facto border along the Himalayas - called the Line of Actual Control, or LAC - which is poorly demarcated.

The 12,000-ton CCG-5901, along with its sister ship CCG-2901 is the world's largest Coast Guard vessel and three times heavier than the U.S. Coast Guard's Legend-class cutters, earning it the nickname ...