The U.S. Navy released this video showing flight operations aboard a P-8A Poseidon over the South China Sea on May 20, 2015. During the flight, the crew documented several warnings issued by China's navy to leave the area. (U.S. Navy)

The Navy has released video that shows how closely the Pentagon is tracking China’s military expansion in the region, one day after news emerged that the Chinese navy repeatedly warned a U.S. surveillance plane to leave a contested area of the South China Sea.

The video was taken in a P-8A Poseidon plane, a Boeing 737 aircraft that has been modified to fight submarines and surface ships, and gather intelligence. A member of the Navy points out the construction of a runway and other facilities in the Spratley Islands in the video.

[Chinese warnings to U.S. plane hint of rising stakes over disputed islands]

The plane, which also was carrying a TV crew from CNN, was warned to leave airspace eight times by the Chinese, who have been constructing man-made islands to expand the country’s territorial reach and influence. Beijing claims sovereignty over much of the South China Sea, but that is contested by a number of other nations, including the Philippines, Vietnam and Taiwan.


A member of the U.S. Navy points out on a video screen how the Chinese are building a runway in the South China Sea. (Screen grab from video released by the U.S. Navy)

The warnings are the latest in a series of encounters between the Chinese and other militaries in the region in the last year. In one case, a Chinese J-11B fighter jet buzzed another P-8A plane last August, drawing a rebuke from officials at the Pentagon.

[What it looks like when a Chinese fighter jet buzzes your plane]

Chinese and U.S. defense officials met late last summer to discuss ways to avoid provocative actions that could lead to the use of military force.