JOINT BASE PEARL HARBOR, Hawaii (AP) — Defense Secretary Ash Carter says China's campaign to build artificial islands in the South China Sea is uniting other countries in the region and spurring calls for the U.S. to get more involved there.

And here's what Carter is saying about recent Chinese complaints about American military flights over the islands: "There should be no mistake, the United States will fly, sail and operate wherever international law allows."

His comments come after the Chinese protested the flight last week of a U.S. surveillance aircraft over Fiery Cross Reef.

And Carter's words are signaling a sharp start to his 11-day overseas trip that will take him across the Asia-Pacific with stops in Singapore, Vietnam and India.