President Obama on Tuesday signed two executive orders on equal pay for women, using the event to mock Republicans as out of touch on the issue of paycheck fairness.

“You'll hear all sorts of excuses -- they're childbearing, they're choosing to do this ... she was doing the same job,” Obama said at the White House, slamming his GOP rivals.

“A woman’s got to work about three more months in order to get what a man got,” the president added. “That’s like adding an extra six miles to a marathon.”

The executive orders prevent federal contractors from discriminating against employees for discussing wages and require the Labor Department to organize salary information based on race and sex.

Obama's actions come ahead of a Senate Democratic push to pass the Paycheck Fairness Act, which would expand anti-discrimination initiatives for all workers, not just federal contractors.

Obama on Tuesday repeated the White House argument that women earn 77 cents for every dollar a man is paid.

However, the White House has been on the defensive after a recent American Enterprise Institute study showing that female employees at the White House earn 88 cents for every dollar men receive.

And conservatives say the White House's statistic is misleading because it does not account for differences in jobs that men and women choose to accept.

Obama did not address that criticism Tuesday, but instead used his speech to slam Republicans as unconcerned with paycheck fairness and the plight of the working poor -- a message that will serve as the centerpiece of Democrats' pitch to voters in November's midterms.

“It’s not a myth — it’s math,” Obama said of the pay gap, dismissing the Republican message as “you’re on your own.”

Even if it passes the Senate, the Paycheck Fairness Act is unlikely to go anywhere in the Republican-controlled House.

But Obama predicted that Republicans would soon feel pressure from voters on the issue.

"Equal pay for equal work," Obama said. "It’s not that complicated."