President Barack Obama will deliver a tough message to China during a summit with Southeast Asian countries next week that disputes in the South China Sea must be resolved peacefully and not with a big nation "bullying" smaller neighbors, the White House said on Tuesday.

Obama will also address North Korea's "provocations" — a nuclear test last month and a rocket launch on Sunday — when he hosts the leaders of the Association of Southeast Asian Nations in California on Monday and Tuesday, aides said.

Ben Rhodes, Obama's deputy national security adviser, said the president will reiterate that territorial disputes over the area, where China and several Southeast Asian states have overlapping claims, must be handled through negotiations and be consistent with international norms.