Sen. Lindsey Graham, the chairman of the Senate Judiciary Committee, on Wednesday said he will invite President Trump’s personal lawyer Rudy Giuliani to testify before his panel about information he’s gathered on corruption in Ukraine.

“I’m going to be reaching out to Rudy, writing a letter saying you’re welcome to come to this committee, if you have something you’d like to share about corruption,” Graham told reporters.

The South Carolina Republican said Giuliani’s appearance “would be up to him” and he wouldn’t be compelled to testify.

Giuliani has been traveling in Ukraine since spring to investigate Joe Biden over allegations the former vice president withheld $1 billion in financial assistance unless a top Ukrainian prosecutor was fired.

At the time, Biden’s son, Hunter, was working for Burisma Holdings, a Ukrainian energy company.

Biden’s role in the ouster of Viktor Shokin is at the center of the articles of impeachment being debated in the House.

Democrats allege Trump, in a July 25 phone call with Ukrainian President Volodymyr Zelesnky, dangled $391 million in military aid to pressure Zelensky to announce an investigation into the Bidens.

Giuliani, in recent interviews, said he lobbied Trump to oust Marie Yovanovitch, the former ambassador to Ukraine, because she was impeding investigations into corruption in Ukraine.

Yovanovitch, who was recalled in April, was blocking visas for former Ukrainian officials to travel to the US to present evidence to him and federal authorities about the Bidens.

“I believed that I needed Yovanovitch out of the way,” Giuliani told The New Yorker in a report published Monday. “She was going to make the investigations difficult for everybody.”

Meanwhile, Secretary of State Mike Pompeo said he would be willing to testify and produce documents during a Senate impeachment trial of Trump “if that’s appropriate and required by law.”

He made the comments at a State Department news conference as the House was debating impeachment.