President Barack Obama has laid a wreath at a memorial honouring those killed in the attack on Pearl Harbour in 1941.
The President was joined at the USS Arizona Memorial by his wife, Michelle, late in the afternoon.
After a moment of silence, the Obamas scattered flower petals in the water.
This year marks the 70th anniversary of the Japanese attacks, which claimed the lives of 2,390 Americans and brought the United States into the Second World War.
The President is in Hawaii for his annual Christmas holiday.
Several White House staff members who travelled to the Honolulu area with Mr Obama joined the President at the Pearl Harbour memorial.
Earlier, Mr Obama took his family to the beach, then stopped for shave ice, a Hawaiian version of the snow cone.