In an interview with WABC radio host Rita Cosby, Lewandowski firmly denied any wrongdoing and said he would testify either Wednesday or Thursday. Lewandowski also told Cosby that he had not been contacted by special counsel Robert Mueller's team.
He didn't specify the committee he'll appear before, but sources have told CNN he is expected to testify before the House Intelligence Committee.
"I'm not concerned at all because I have nothing to hide," Lewandowski said, according to excerpts of the interview provided by WABC. "I don't back down from a fight and I have nothing to hide, so I will be fully prepared to answer any question about my tenure at the Trump campaign."
Lewandowski insisted that he "didn't collude or cooperate or coordinate with any Russian, Russian agency, Russian government or anybody else, to try and impact this election" and said that he'd "be happy to come out and set the record straight about my lack of involvement with any type of foreign entity."
The former Trump campaign official added that he had "nothing to hide, and what I want to do is make sure that if anybody did collude or cooperate to try to impact the outcome of a US election, those people spend the rest of their lives in jail."
Regarding Mueller's investigation, Lewandowski said he had not been contacted, "but let me give the same message to everybody -- I will speak to anybody who wants to have a conversation about it, because there's nothing to hide here, and it's time to put this whole issue behind us."
"If you need to talk to people who were involved in the campaign to bring that to a resolution, let's do that. But it's time to bring this investigation to a close," Lewandowski said.
Cosby asked Lewandowski whether he thought President Donald Trump should sit for an interview with Mueller's team, and how the President might withstand scrutiny from the special counsel's investigators.
"The President is very capable in these scenarios," Lewandowski answered. Pressed on the subject, Lewandowski said "of course" Trump could handle an interview with Mueller's team, "but the question is ... is that what is in the best interest of the American people?"
"There's no question to me, that if he were to sit down and tell that team exactly what took place, and I was there for it, they will come to the same conclusion that everybody else has already come to, which is there is no collusion," Lewandowski said.
Lewandowski has already appeared before the Senate Intelligence Committee
, testifying behind closed doors in a mid-October session with committee staff.
The former Trump campaign manager has repeatedly denied having any contacts with foreign entities regarding election interference. Lewandowski was still on the Trump campaign at the time of the June 2016 meeting between top Trump campaign officials and a Russian lawyer who promised dirt on Hillary Clinton, though Lewandowski was not at the meeting.