According to the 1907 Gentlemen's Agreement between the United States and Japan,

It was an informal accord by the United States and the Empire of Japan in which the United States of America won’t enforce restriction on Japanese immigration, and Japan would not permit more people to emigrate to the U. S. The goal was to decrease tensions between the two powerful Pacific nations. The agreement was never approved by Congress. Later it was ended by the Immigration Act of 1924.