"I have to make this decision with my client (Donald Trump - ed.) within the next week or so," said Giuliani.
His comment came the day after Graham had announced his plans to invite the former New York City mayor to testify in the Senate Judiciary Committee.
The senator had previously indicated that he would like to find out "everything that is happening in Ukraine," but did not think that the Senate would have to investigate.
"Given the behavior of the House of Representatives, it is time for the Senate to inquire into corruption and other abuses related to Ukraine," Graham said in a series of tweets.
As we reported earlier, Rudy Giuliani is prepared to testify in the House Intelligence Committee's investigation into the president's impeachment only if his client, Donald Trump, agrees. This was stated by Giuliani in an interview with ABC News.