President Donald Trump's lawyer, Rudy Giuliani, said special counsel Robert Mueller should complete his investigation by September to avoid influencing midterm congressional elections, a mistake Giuliani says former FBI director James Comey made in handling the Hillary Clinton probe.

"If he doesn't file his report by Sept. 1 or mid-September, he is clearly doing a Comey," Giuliani told reporters at the White House Wednesday after attending a fitness event there. "People should have an answer even if they put together whatever the heck they have."

He added that Mueller should meet the deadline regardless of whether Trump agrees to an interview with Mueller, who is investigating Russian meddling in the 2016 presidential election and whether anyone close to Trump colluded with the Russians.