A Defense Ministry statement Saturday says the U.S. is deliberately raising tensions in the disputed region. It demanded Washington immediately take measures to prevent such incidents and damage to relations between the two nations' militaries.
As it has in past, the ministry also said it would take whatever necessary measures to protect China's sovereignty and security.
The U.S. takes no official stance on sovereignty claims in the strategically crucial sea that China claims almost in its entirety. However, Washington maintains that China's seven newly created islands do not enjoy traditional rights including a 12-nautical mile (22-kilometer) territorial limit.
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