US President Barack Obama has signed his first bill into law since he assumed the top office, making a historic provision that ensures equal pay for both men and women.

"This bill is an important step -- a simple fix to ensure fundamental fairness to American workers," Obama said on the occasion. Obama was flanked by key women lawmakers including the head of House of Representatives, Nancy Pelosi, eminent women who worked for passage of the bill and First Lady, Michelle Obama.

"In signing this bill today, I intend to send a clear message -- that making our economy work means making sure it works for everyone," Obama said at the bill signing ceremony.

"There are no second class citizens in our workplaces, and it's not just unfair and illegal but bad for business to pay someone less because of their gender, age, race, ethnicity, religion or disability," he said.

Equal pay isn't just an economic issue for millions of Americans and their families, but also for America's fundamental ideals, he argued. Equal pay is by no means just a women's issue; it's a family issue, he said.

"It's about parents who find themselves with less money for tuition or child care; couples who wind up with less to retire on; households where, when one breadwinner is paid less than she deserves, that's the difference between affording the mortgage  or not; between keeping the heat on, or paying the doctor's bills  or not," Obama said.

In this economy, when so many folks are already working harder for less and struggling to get by, the last thing they can afford is losing part of each month's paycheck to simple discrimination, Obama said.

Later speaking at a White House reception hosted by her on this occasion, the First Lady, Michelle Obama, termed it as a historic occasion.

"This legislation is an important step forward, particularly at a time when so many families are facing economic insecurity and instability," she said.

"It's also one cornerstone of a broader commitment to address the needs of working women who are looking to us to not only ensure that they're treated fairly, but also to ensure that there are policies in place that help women and men balance their work and family obligations without putting their jobs or their economic stability at risk," Michelle said.