Giuliani issued a statement aimed at clarifying a Wednesday night CNN interview that appeared to leave open the possibility of improper contacts during the campaign, in light of court filings in the past year that have detailed ties between Trump aides and Russia.
"I represent only the president, not the campaign," he told The Associated Press in an interview. "And I can only speak of what I know, and that is that I have no knowledge that anyone on the campaign illegally colluded with Russia. But I can only speak definitively about the president, as he is my client."
In a separate statement Thursday, he said that "there was no collusion by President Trump in any way, shape or form" and that he had "no knowledge of any collusion by any of the thousands of people who worked on the campaign."
That was an apparent reversal from the television appearance in which he said, "I never said there was no collusion between the campaign or between people in the campaign." He had previously denied any collusion.
It was not clear whether Giuliani in the television interview was reflecting a new position or talking point from the Trump legal team or was making a strategic attempt to get ahead of potentially damaging findings from special counsel Robert Mueller, who has been investigating potential coordination between Russia and the president's campaign.
Either way, the comment reflected a stark turnabout from long-standing denials by the White House and Trump advisers of improper collusion, and it underscored how the president's lawyers have adapted their message and defenses as additional revelations have emerged.
In November 2016, for instance, Trump spokeswoman Hope Hicks said, "There was no communication between the campaign and any foreign entity during the campaign." Trump himself has repeatedly insisted there was no collusion during his successful White House run.
In a Fox News interview last May, Giuliani described the idea of Russian collusion as "total fake news" and said, "Unfortunately, it has become the basis of the investigation. Mueller owes us a report saying that Russia collusion means nothing, it didn't happen."
On Wednesday, Giuliani told CNN that even if some people working on the campaign did something wrong, the president was not part of any collusion.
"There is not a single bit of evidence the president of the United States committed the only crime you could commit here, conspired with the Russians to hack the DNC," Giuliani said, referring to the Democratic National Committee.
Giuliani repeated to the AP on Thursday that there was no collusion "connected to Russian hacking" and that Manafort's sharing of polling data had nothing to do with the campaign or the president.
Giuliani also said the Trump legal team had told Mueller that the president would not answer any additional questions from prosecutors. Trump has so far answered only a limited number of questions in writing. Trump's lawyers have balked at the idea of a face-to-face interview with Mueller's office or having Trump questioned about potential obstruction of justice or other actions he took as president.
"We will not answer any further questions from them," Giuliani told the AP. "We made a definitive refusal. And now they have not gotten back to us in more than a month."
William Barr, Trump's nominee for attorney general, told the Senate Judiciary Committee this week that he wouldn't interfere with a Mueller request to subpoena the president to compel his testimony "if there was a factual basis for doing it."
Giuliani reiterated his desire to have an early look at whatever report Mueller produces at the conclusion of his investigation.
"We do think we should be given a courtesy of seeing it," Giuliani said. "We should see it before it is made public. Not to change it, but to prepare our own report as a rebuttal."