A U.S. government report on human rights violations addressed the issue of so-called maternity harassment in Japan on Thursday, while expressing concern about South Korea's indictment last year of a Japanese journalist over reporting on the country's president.

The 2014 Country Reports on Human Rights Practices, compiled by the State Department, also blasted "numerous outrages and killings" by Islamic State militants as well as the suppression of free speech and crackdowns on activists in countries such as China, Russia and Iran.

The annual report said inequality in employment in Japan remained a "society-wide problem," citing lower wages for women and a small proportion of women holding managerial positions.