Under the Philippines constitution, martial law can be imposed for up to 60 days in circumstances involving an invasion or armed rebellion.

PHILIPPINE President Rodrigo Duterte has announced his “separation” from the United States, declaring he has realigned with China as the two agreed to resolve their South China Sea dispute through talks.

"These special forces, they have to go," Duterte said in a speech during an oath-taking ceremony for new officials.

On Wednesday he is to attend a gala dinner with both Obama and Ban, as well as join a meeting that the two leaders will have with ASEAN heads of state and government.