A memorial service for former U.S. Ambassador to Japan Mike Mansfield, who died Oct. 5 in Washington at the age of 98, was held Wednesday at a hotel in Tokyo.

About 300 people, including diplomats, business people and citizens, attended the service to pay tribute to one of the most respected American ambassadors to Japan.

After serving in the U.S. Congress for more than three decades, Mansfield, then 73, was appointed as the ambassador to Japan in 1977 under the administration of Jimmy Carter. Mansfield served in the post for 11 years -- the longest of any U.S. ambassador to Japan -- and continued to promote diplomatic ties between the two nations after leaving the post.