Philippine President Rodrigo Duterte has banned joint military exercises with the United States in the South China Sea, where American officials seek to aid the Philippines in territorial disputes with China.

“President Rodrigo Duterte has a standing order to us, to me, that we should not involve ourselves in naval exercises in the South China Sea except our national waters, the 12-mile distance from our shores,” Defense Secretary Delfin Lorenzana said in a briefing this week.