A series of new measures aimed at reinforcing the US professional football policies to protect players from discrimination based on sexual orientation have been adopted by the country’s football league.

The US Major Soccer League (MSL) new measures include expanded sensitivity training for players; the display of a Code of Conduct prohibiting discrimination in home and visitor locker rooms; and a centralised complaint system for filing harassment and discrimination complaints.

The league, which represents football’s highest level in Canada and the US, also pledged to protect from retaliation any person who makes a complaint or who cooperates in an investigation.

The new measures are part of the league's 'Don't Cross the Line' anti-discrimination campaign, launched last year.

The initiative "is a strong statement that we are a league that stands against discrimination,” said the MLS chief administrative officer, JoAnn Neale.

"We are committed to providing a safe environment where everyone is treated equally, and with dignity and respect." she added.

The new measures were developed in co-operation with the New York Attorney General Eric Schneiderman, whose office reached similar agreements with the US National Football League (NFL) and Major League Baseball (MLB).

"Harassment and discrimination in the workplace - whether in an office building, on the soccer field or a baseball diamond - are illegal," said Eric Schneiderman in a statement.

"My office is committed to ensuring equal protection under the law for all employees no matter where they work, and I applaud Major League Soccer for working cooperatively with us to promote a culture of inclusion. Together, we are sending a powerful message that discrimination and harassment will not be tolerated in any form in the world of major league sports." he added.