The U.S. Navy's 3rd Fleet will send more ships to East Asia to operate outside its normal theater alongside the Japan-based 7th Fleet, a U.S. official said on Tuesday, a move that comes at a time of heightened tensions with China.

The 3rd Fleet's Pacific Surface Action Group, which includes the guided-missile destroyers USS Spruance and USS Momsen, was deployed to East Asia in April.

More 3rd Fleet vessels will be deployed to the region in the future, said a U.S. official who requested anonymity. He and a second official said the vessels would conduct a range of operations, but gave no details.