Washington (CNN) Hillary Clinton slammed President Donald Trump on Friday after his personal attorney Rudy Giuliani admitted to asking Ukraine to investigate former Vice President Joe Biden, who is currently the Democratic front-runner to challenge Trump in next year's presidential election.

"The president asked a foreign power to help him win an election. Again," the former secretary of state tweeted, referring to Trump's call during the 2016 race for Russia to look into Clinton's deleted emails.

The president asked a foreign power to help him win an election.



Again.https://t.co/EjkE84oCCF — Hillary Clinton (@HillaryClinton) September 20, 2019

Clinton's tweet included a video of Giuliani's comments on CNN's "Cuomo Prime Time" Thursday, when Chris Cuomo pressed the former New York mayor over conversations he'd had with a Ukrainian official about Biden's possible role in that government's dismissal of a prosecutor who had investigated the former vice president's son, Hunter.

"Did you ask the Ukraine to investigate Joe Biden?" Cuomo asked Giuliani.

"No, actually I didn't. I asked the Ukraine to investigate the allegations that there was interference in the election of 2016 by the Ukrainians for the benefit of Hillary Clinton, for which there is already a court finding," Giuliani responded.

Read More