Obama, at Pearl Harbor, warns against 'urge to demonize' others

US President Barack Obama on Tuesday warned against the "urge to demonize those who are different" as he hosted the leader of foe-turned-ally Japan for a solemn visit to Pearl Harbor.

Obama, who will leave office next month, also hailed the alliance between the two nations, saying it had "never been stronger."

In remarks that echoed with history and America's current hypercharged politics, Obama told Japanese Prime Minister Shinzo Abe that "the character of nations is tested in war, but it is defined in peace."

"Even when hatred burns hottest, even when the tug of tribalism is at its most primal, we must resist the urge to turn inward. We must resist the urge to demonize those who are different," Obama said.

"I welcome you here in the spirit of friendship," he told Abe.

"I hope that, together, we send a message to the world that there is more to be won in peace than in war, that reconciliation carries more rewards than retribution."