Biden administration officials have decided to reject a vague new assertion by China that the Taiwan Strait is not "international waters” and are increasingly concerned the stance could result in more frequent challenges at sea for the democratically governed island, according to people familiar with the matter.

Chinese officials have made such remarks repeatedly in meetings with U.S. counterparts in recent months, Bloomberg reported last week. That raises the prospect that China could be preparing a new challenge to U.S. regional influence and military power in a key area of discord between the two countries.

China has long asserted that the Taiwan Strait is part of its exclusive economic zone, and takes the view there are limits to the activities of foreign military vessels in those waters. While China regularly protests U.S. military moves in the Taiwan Strait, the legal status of the waters previously wasn’t a regular talking point in meetings with American officials.