Booker's campaign announced Wednesday the Democrat would accept invitations to a televised forum on Aug. 5 and a radio forum on Aug. 8, just one week out from Election Day. However, an aide with the campaign clarified that his decision did not preclude scheduling further forums.

Democratic opponent Frank Pallone (D-N.J.) had earlier Wednesday accepted invitations to five debates, including the two Booker accepted.

Booker remains the front-runner in the race for the Democratic nomination in every poll, all of which give him a significant double-digit lead.

New Jersey political observers agree, however, that debates could be a weak point for the mayor, as he has less experience than his congressional opponents with some of the federal and international policy issues that would come up in a candidate forum.

His choice to engage in only two debates, just a week out from the Aug. 13 primary, minimizes the chance that any missteps during a forum will affect his standing in the race.

Holt spokesman Thomas Seay knocked Booker for accepting, amid "nearly a dozen proposals,' two "that will reach only a tiny fraction of New Jersey voters."

"That's especially troubling because the mayor has never before run for federal office, has never expressed views on many federal issues, and has not shared a single position statement on his campaign website," he said.

"It’s unsettling. Somehow, political consultants have taken a man who once ran into a burning building and convinced him to run away from policy debates."

Holt has not yet accepted any debates, but Seay said he hopes to schedule as many as possible.

Booker spokesman Kevin Griffis pushed back against the idea that Booker doesn't have significant policy experience.

"As Newark’s mayor, Cory Booker deals every day with the real-world impact of federal policy. What we look forward to discussing in this race is the progress he’s made in curbing gun violence, creating jobs and improving schools to improve people’s lives, progress often made despite the headwinds coming from Washington," he said.

--This post was updated at 9 a.m. on Friday.