KERMIT, W.Va. ― Sen. Elizabeth Warren (D-Mass.) addressed a New York Times report that President Donald Trump’s personal lawyer plans to visit Ukraine to push for things that could benefit Trump, saying, “Rudy Giuliani should just back off.”

“I just think it is highly unethical for the president’s personal lawyer to go meet with officials from a foreign government to see if they can influence, somehow, the upcoming presidential election,” Warren, a 2020 Democratic presidential candidate, said during a campaign stop in Kermit, West Virginia, on Friday. “We’ve had enough of that.”

The New York Times reported Thursday on Giuliani’s plans to travel to Kiev, where he hopes to meet with Ukrainian President-elect Volodymyr Zelensky, a comedian with no political experience who recently defeated incumbent Petro Poroshenko. Giuliani hopes to discuss the origin of special counsel Robert Mueller’s investigation of interference by Russia in the 2016 election in a move that aims to both discredit the investigation and help Paul Manafort, who ran Trump’s campaign and is in prison for illegal foreign lobbying and laundering money paid to him by Ukrainian officials.

“We’re not meddling in an election, we’re meddling in an investigation, which we have a right to do,” Giuliani told the Times.

He’s also pushing for a probe into former Vice President Joe Biden’s actions toward a top Ukrainian prosecutor as his son Hunter acted as a board member for an oil and gas company owned by a Ukrainian oligarch. Trump has predicted he could face off against Joe Biden in the 2020 presidential election.

Giuliani defended his plans Friday in a phone call to CNN.

“I don’t want any favors, I just want this investigated,” Giuliani said.