The Night of the Samurai (The Wild Wild West)

From J-Wiki

Wild Wild West (1967) episode entitled "Night of the Samurai" (S3 E6).

Episode aired Oct 13, 1967

A valuable samurai sword being returned to a Japanese prince by the United States' government is stolen and must be found by Jim and Artemus before the prince leaves the next day, to avoid an explosive political falling out with the government of Japan.