Philippine President Rodrigo Duterte has described his dilemma in dealing with a more powerful China in territorial disputes in the South China Sea, saying he has few options other than to order troops to "prepare for suicide missions" if a Philippine-occupied island comes under threat.

Duterte reminded China in a speech Thursday of its closer ties with the Philippines under his leadership, but said if an island occupied by Filipinos in the disputed waters is threatened, "things would be different." Duterte has adopted a non-confrontational approach in territorial spats with China while seeking infrastructure funds and investment.

Duterte said in reference to the island, "If you touch that, that's a different story. I can tell my soldiers 'prepare for suicide missions.'"

Six governments claim territories in the South China Sea.