U.S. Navy Sec concerned about China naval build-up

The United States is concerned about China's naval build-up including submarine production because of a lack of clarity about Beijing's intentions, U.S. Navy Secretary Donald Winter said on Friday, one day after a U.S. nuclear-powered aircraft carrier was deployed to a Japanese port.

The USS George Washington arrived at its new home of Yokosuka, near Tokyo, on Thursday to replace one of the oldest active ships in the U.S. Navy.

"We are concerned by both the number of ships that are being constructed, but we are also concerned by what appears to be a lack of transparency ... because we just simply don't understand the rationale for many activities they are engaged in," Winter told reporters when asked about China's military expansion, particularly in the Western Pacific.

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