White House press secretary Jay Carney on Monday said he had not spoken to President Obama about the split in former Vice President Cheney’s family over gay marriage, saying that it could be a “tough issue for a lot of families.”

Carney tried to sidestep questions about the Cheney family’s public fight over same-sex marriage, but told reporters that marriage equality was an “American value” and credited Cheney for publicly supporting gay marriage.

The Cheney family dispute over the issue erupted over the weekend after one of the former vice president's daughters, Mary Cheney, who is in a same-sex marriage, publicly criticized her sister, Liz Cheney, a Wyoming Senate candidate who opposes gay marriage rights.

In an interview with Fox News Sunday, Liz Cheney said that she opposed same-sex marriage, despite her sister's own relationship.

“I love Mary very much. I love her family very much. This is just an issue on which we disagree,” said Liz Cheney.

In a Facebook post, Mary Cheney responded, writing “Liz — this isn’t just an issue on which we disagree — you’re just wrong — and on the wrong side of history.”

Liz Cheney is seeking to unseat incumbent Sen. Mike Enzi, R-Wyo., in the GOP primary.

Dick and Lynne Cheney earlier Monday sought to downplay the controversy and defended their daughter Liz.

“This is an issue we have dealt with privately for many years, and we are pained to see it become public,” said the Cheney parents in a statement.

“Liz has always believed in the traditional definition of marriage. She has also always treated her sister and her sister's family with love and respect, exactly as she should have done. Compassion is called for, even when there is disagreement about such a fundamental matter, and Liz's many kindnesses shouldn't be used to distort her position,” they added.

Dick Cheney in 2011 publicly endorsed gay marriage, a year before Obama became the first sitting president to also do so.

Asked about the Cheney’s fight, Carney took the opportunity to press the GOP-controlled House to pass legislation which would bar discrimination on the basis of sexual orientation in the workplace.

“Like so many Americans, former Vice President Cheney has come to view equality as something that we need to make a fact and not just an aspiration and that is where the president is and that is reflected in his very strongly held view that the House of Representatives should follow the Senate's lead and pass the Employment Non-Discrimination Act,” said Carney.

“In the not too distant future we in this country will look back at this moment and pretty clearly realize that those who opposed ENDA are wrong,” he added.

“There’s no question there’s been enormous progress,” Carney said. “More progress needs to be made.”