Joe Biden expressed anxiety about a large number of candidates appearing in the upcoming Democratic presidential debate.

“The deal was, well, no more than 10 people on the stage for three hours. Well, now there’s 12. They’re supposed to, if more than 10, they’re supposed to divide it into two. At least if you had a debate with five other people you might actually get a chance to say something. But I’m going to try to be more declarative, but not argumentative,” Biden said at a high-dollar Los Angeles fundraiser, according to a pool report.

The 12-person October debate stage on Tuesday will be the largest ever. Democratic debates in June and July featured 20 candidates over two nights, and only 10 candidates qualified for the September debate.

Biden voiced frustration about short time allotments to give complicated answers, particularly on questions about his record.

“But, so, when someone says, you know, you know, ‘Are you still beating your wife?’ And, and I go, ‘I have a long explanation,’ and they say, 'You got 30 seconds to answer.’ And you say, ‘No. And then, wait a minute, what’d I just say? No, I’m not still beating my wife.’ But so, I’ve had, I’ve had some difficulties on knowing to counterattack,” Biden said.

In previous debates, California Sen. Kamala Harris attacked Biden for working with segregationist senators in the 1970s to oppose busing desegregation, and New York Sen. Kirsten Gillibrand criticized a 1981 Biden op-ed that argued a child tax credit would result in the "deterioration of family."

“One of the problems I’m finding, I’ve got to be more aggressive,” Biden said. “Which is good, I’m not complaining, I’m a big boy.”

Though 12 candidates have qualified for the October debate, Hawaii Rep. Tulsi Gabbard on Thursday threatened to boycott it. The Democratic National Committee and "corporate media" are "attempting to replace the roles of voters in the early states using polling and other arbitrary methods which are not transparent or democratic," Gabbard argued.

CNN and the New York Times host the October Democratic presidential debate on Tuesday at Otterbein University in Ohio.