John S. McCain conducts Christmas Eve FONOP in South China Sea

Sailors observe from the foc’s’le as the Arleigh Burke-class guided-missile destroyer USS John S. McCain (DDG 56) makes its approach towards the dry cargo and ammunition ship USNS Alan Shepard (T-AKE 3) prior to a replenishment-at-sea on Oct. 22, 2020, in the South China Sea. (MC2 Markus Castaneda/Navy)

The U.S. Navy warship John S. McCain conducted a freedom of navigation operation, or FONOP, Christmas Eve in the South China Sea, its second such operation this week.

The guided-missile destroyer “asserted navigational rights and freedoms near Vietnam in the vicinity of the Con Dao Island in the South China Sea” on Thursday, according to the Japan-based U.S. 7th Fleet.

“The ship conducted normal operations within Vietnam’s claimed territorial seas to challenge excessive maritime claims and preserve access and navigational freedoms consistent with international law,” the command said in a statement.

While China and other South China Sea nations increasingly try to claim traditionally international waters as their own, the U.S. Navy regularly sends ships through to bolster the claim that such waters are open to all.

On Tuesday, John S. McCain steamed near the contested Spratly Islands in the South China Sea in order to challenge similar excessive maritime claims.