The U.S. Marine Corps has deployed an unspecified number of advanced F-35 stealth fighter aircraft armed with laser-guided bombs to the Philippine Sea for a training exercise, Indo-Pacific Command said Wednesday. 

"U.S. @PacificMarines with @31stMEU assigned to @USPacificFleet amphibious assault ship USS America #LHA6 unleash F-35 fighter aircrafts armed with GBU-49 bombs in the Philippine Sea. #SemperFI #Lethality #FlyMarines," the command wrote on Twitter.

It said in a follow-on tweet that the forces were engaged in "conducting routine training with the F-35s aboard the USS America."

"Thank you and we apologize for the confusion #FreeandOpenIndoPacific," it said.

The USS America is an amphibious assault ship capable of carrying aircraft including attack jets and infantry transportation aircraft like the V-22 Osprey.

The drill comes amid continually high tensions between the U.S. and China as Washington seeks to maintain what it calls freedom of navigation in the region while Beijing seeks to impose restrictions based on what it says are its claims to the waterways.