Japan's Prince Akishino and Princess Kiko are visiting a memorial dedicated to nine people killed when a U.S. Navy submarine rammed into a Japanese fisheries vessel off Hawaii in 2001.

The prince on Monday laid a white wreath at the memorial in Honolulu's Kakaako Waterfront Park and spoke to members of the Honolulu community.

All nine killed were on board the Ehime Maru, a training vessel for fisheries students from Ehime, Japan. The submarine's rudder sliced into the ship's hull.

A Navy investigation found the USS Greenville's captain had rushed through mandatory safety procedures while demonstrating an emergency surfacing drill for the benefit of civilians touring the submarine.

Earlier in the day, the couple laid a wreath at the National Cemetery of the Pacific in remembrance of fallen U.S. troops.