The USS Nimitz and USS Ronald Reagan Carrier Strike Groups are conducting dual carrier operations in the Philippine Sea and South China Sea," said Lt. Joe Jeiley, a spokesman for the Seventh Fleet. "Operating two carrier strike groups in the Philippine Sea and South China Sea provides advanced training opportunities for our forces and provides combatant commanders with significant operational flexibility should those forces be called upon in response to regional situations.
"The presence of two carriers is not in response to any political or world events. This advanced capability is one of many ways the U.S. Navy promotes security, stability, and prosperity throughout the Indo-Pacific."
"America agrees with our Southeast Asian friends: The PRC's (People's Republic of China) military exercise in disputed waters of the South China Sea is highly provocative. We oppose Beijing's unlawful claims. Period," Secretary of State Mike Pompeo tweeted on Friday.
The Pentagon said in a statement Thursday that China's "military exercises are the latest in a long string of PRC actions to assert unlawful maritime claims and disadvantage its Southeast Asian neighbors in the South China Sea."
The Paracel Islands are claimed by China, Vietnam and Taiwan, and the US has long said Beijing has militarized the islands in the South China Sea via the deployment of military hardware and construction of military facilities.
Officials said the US military exercises will not be conducted close to any of the contested islands in the region.
While the US Navy routinely operates in the area, the operation of two nuclear-powered aircraft carriers -- the USS Nimitz and USS Ronald Reagan -- represents a significant show of force and comes amid heightened tensions between Washington and Beijing over a number of areas, including Hong Kong.
This story has been updated with additional information.