Red Sun (1971) on Netflix

The story takes place in Arizona, around 1870. Link and Gotch are two ruthless robbers that attack along with their men at the train which carries the ambassador of Japan over to Washington. During the robbery, Gotch takes a very valuable gold sword, which is a gift from the emperor to the president of the U.S. and tries to kill Link, so that he can take all the money for himself. Now Kuroda (the only survivor of the samurais that escorted the ambassador) and Link must leave their differences aside and work together. They both want to find Gotch, but for different reasons: Kuroda wants to take back the sword, and Link wants the stolen money. All this must be done in seven days, or the samurai will kill Link and himself.