The U.S. Navy plans to send a ship to within 12 nautical miles of disputed islands in the South China Sea, a U.S. official confirmed to Fox News -- in an apparent challenge to Beijing's territorial claims.
Reuters first reported that the Navy planned within 24 hours to send a destroyer near the Spratly Islands, an archipelago that China aggressively has laid claim to by building airstrips and other features on top of reefs.
Reuters reported that the ship probably would be joined by a surveillance plane.
U.S. military officials were angry over the leak, but one official reluctantly confirmed the plans.
Officials said the USS Lassen, a Navy destroyer, would be the closest ship in position to carry out the operation.
Asked for comment at Monday's briefing, White House Press Secretary Josh Earnest would not confirm any operational decisions.
But he stressed that ensuring freedom of navigation is critically important to a global economy -- and said that is the principle that's at stake.
The dispute over the strategic waterways of the South China Sea has intensified over the last year, pitting a rising China against its smaller and militarily weaker neighbors who all lay claim to territory mostly in the Spratly and the Paracel islands.
The area is one of the world's busiest shipping routes, rich in fish and potential gas and oil reserves.
Satellite images taken in early September purportedly showed construction of a third Chinese airstrip in the South China Sea, which would be of particular concern to the Philippines.
The matter of the artificial islands, along with cybersecurity concerns, was a top agenda item when Chinese President Xi Jinping met with President Obama last month on a state visit at the White House.
-- Fox News' Jennifer Griffin and The Associated Press contributed to this report.