The White House has sought to cut down on any airing of differences between the Defense Department and the National Security Council on the sensitive issue, the defense officials said, though they noted that there was no official "gag order."
The White House was particularly concerned that there be no public disagreements between the bodies in the run-up to a visit to Washington by Chinese President Xi Jinping last week as part of President Barack Obama's Nuclear Security Summit.
Asked for comment, a senior administration official denied that there was any silencing of officials and said the issue was merely one of coordinating a message across several departments.
"The administration -- from (the Department of Defense), to the State Department, to the NSC and places in between -- recognizes the value of message discipline, especially when it comes to sensitive issues. It's no secret that we coordinate messaging across the inter-agency on such priorities," the official said. "But efforts to be consistent are a far cry from a 'gag order.' To be clear, there never has been a 'gag order.'"
The clampdown on public statements was first reported
by the independent Navy Times.
Defense officials told CNN that senior commanders privately expressed differences with the White House on the U.S. response to China's expanding claims in the South China Sea, including pushing for more robust Navy action in and around man-made islands that China has constructed. China has been building the islands in contested waters and then claiming control of the surrounding water and airspace.
However, one defense official described these differences as "healthy" and said they did not signal an acrimonious relationship between the military and the NSC or the White House.
Adm. Harry Harris Jr., commander of U.S. Pacific Command, issued a statement saying, "Any assertion that there is a disconnect between U.S. Pacific Command and the White House is simply not true. My private counsel to the President and the Secretary during classified deliberations wouldn't be worth much if it weren't private. Maintaining that trust is why senior military admirals and generals won't discuss our counsel in public."
At the same time, the U.S. has recently announced new steps to reassure Asian allies nervous in the face of Chinese territorial claims.
On Friday, Defense Secretary Ash Carter announced new military aid to the Philippines. The aid involves equipment to allow Filipino ships and aircraft to better track Chinese military activity, including around the Scarborough Shoal, which is claimed by both China and the Philippines and lies around 130 miles from the Philippines' capital of Manila.
In March, the U.S. and Philippines welcomed a deal -- called an Enhanced Defense Cooperation Agreement -- that will allow the Pentagon to deploy conventional forces to the Philippines for the first time in decades and use parts of five military installations: Antonio Bautista Air Base, Basa Air Base, Fort Magsaysay, Lumbia Air Base and Mactan-Benito Ebuen Air Base.