Carly Fiorina is not letting up on attacking Hillary Clinton.

Fiorina, who has carved out a niche among likely Republican candidates for president as a reliable and vocal foe of Clinton, took aim at the former secretary of state Monday on women's issues, which will likely be central to Clinton's presidential campaign.

At a panel discussion in Washington led by the conservative group Concerned Women For America, Fiorina said Clinton's attention to women extends only to Democrats, recalling an Iowa campaign event last year at which Clinton stumped for Rep. Bruce Braley over Republican Joni Ernst.

"Hillary Clinton said it's not enough to be a woman, you have to be a woman who believes — and she then went through the litany of liberal beliefs," Fiorina said. "So, in essence what she was saying is, unless you're on our team, we don't think you count."

At the campaign event in October 2014, Clinton said regarding Ernst: "It's not enough to be a woman. You have to be committed to expand rights and opportunities for all women."

Fiorina's remarks came during a discussion of the "war on women" trope in politics and how Republicans might better appeal to women voters, a demographic among which the party has lagged in recent election cycles.

Her remarks also echoed those she delivered over the weekend at a conservative women's event in Iowa, where Fiorina has spent a substantial amount of time laying the groundwork for her likely campaign. There, Fiorina said Clinton "will play that gender card all day long."

In a field of Republican candidates bursting with men, Fiorina stands out as the sole woman likely to run as a Republican this cycle. The distinction puts her at a potential advantage to attack Clinton on women's issues, a role Fiorina has appeared to embrace.

"The Democrats and Hillary Clinton have made gender an issue with their ridiculous 'war on women,'" Fiorina told the New York Times recently. "I think if Hillary Clinton faces a woman opponent, she will get a hitch in her swing."