Japanese Prince Akishino delivered a speech Thursday to commemorate the life and contribution of the first Japanese immigrants to Hawaii, at a ceremony in Honolulu marking the 150th anniversary of their arrival.

"As we look back at the history of Japanese immigration, we must never forget the tremendous contribution that the Issei and the Nisei made to the development of Hawaii, while struggling to overcome various difficulties," Prince Akishino, the younger son of Emperor Akihito, said in English.

The Issei were the first generation of immigrants and the Nissei were their children.

About 150 Japanese immigrants, or "gannenmono," emigrated from Japan in 1868, the first year of the Meiji era, to work as laborers at the request of the Kingdom of Hawaii.

Since they departed Japan without permission from the new government, they did not receive support from Japan and struggled as they worked on plantations in Hawaii.

"On this occasion, I wish to express my renewed deep respect for your continued efforts to strengthen the friendship and goodwill between Japan and Hawaii, and between Japan and the United States of America," the prince also said.

(Prince Akishino, center, and his wife Princess Kiko, right, visit a botanical garden.)

The prince and his wife Princess Kiko are on a six-day official visit to the United States, mainly to attend events to commemorate the anniversary of the first Japanese immigrants. It is their first official visit to the United States as a couple.

The couple also met with students who majored in the Japanese language at the University of Hawaii and inspected the university's botanical garden.

The couple are scheduled to leave the islands Friday afternoon.

The prince will be first in line to the throne after the accession of Crown Prince Naruhito, his elder brother, following the emperor's abdication on April 30, 2019.