Failed 2016 White House hopeful Hillary Clinton accused President Donald Trump on Friday of seeking the assistance of a foreign government to win a presidential election for a second time.

“The president asked a foreign power to help him win an election. Again,” Clinton wrote on Twitter.

The president asked a foreign power to help him win an election. Again.https://t.co/EjkE84oCCF — Hillary Clinton (@HillaryClinton) September 20, 2019

In her tweet, Clinton seemingly referenced a joke then-candidate Trump told in 2016 in which he asked Russia to locate his Democrat rival’s emails on a private server. “Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing. I think you will probably be rewarded mightily by our press,” he said at the time.

The former secretary of state’s comment came in response to an interview in which Rudy Giuliani, the president’s personal attorney, told CNN that he requested the Ukrainian government to probe possible wrongdoing which may have involved former vice president and 2020 frontrunner Joe Biden.

“I didn’t ask them to look into Joe Biden,” Giuliani told host Christopher Cuomo on Thursday. “I asked them to look into the allegations that related to my client, which, tangentially, involved Joe Biden in a massive bribery scheme, not unlike what he did in China.”

In 2016, Biden, according to the New York Times, threatened to withhold $1 billion in U.S. loan guarantees unless Ukrainian prosecutor General Yuriy Lutsenko was removed. Lutsenko was probing possible wrongdoing of an energy firm of which Biden’s son, Hunter, was a board member.

Last month, Giuliani revealed he spoke to a Ukrainian official about Biden’s potential role in the prosecutor’s removal.

“The only thing I asked about Joe Biden is to get to the bottom of how it was that Lutsenko … dismissed the case against [Ukrainian’s Anti-Corruption Action Centre],” he said.