It is already the law in the United States.
In the same job, men and women are paid the same.
Maybe Iceland is requiring something different.
It they require that men doing commercial piloting be paid the same as secretaries, it is not equal pay.
Men and women are only paid the same if their work is of equal quality. This is explained if you read the article about Iceland. There are things taken into consideration when equality of salaries is determined. Longevity, time on and in the position, quality of work, productivity, and even things such as attendance and promptness.
This law is nothing but another feel good law passed by politicians to make them look good.