"He roped himself into a certain group of people," the president told Fox Sports Radio on Tuesday. "Some people would say that men are insulted by that. And some people would say it's fine."
Mr Trump, who trails the former vice president nationally and in the key swing states that experts say will decide the election, appeared to shrug off Mr Biden's coming VP announcement.
"People don't vote for the vice president," he said, referring to a political adage that voters care almost exclusively about the name at the top of the ticket.
"In the end, it doesn't really matter," Mr Trump said.
He appeared on the sports-focused network a day after he called on the NCAA and its major conferences to carry on with their football seasons.
The so-called "Power Five" conferences are reportedly nearing a fall shutdown, and the smaller Mid-American and Mountain West conferences already have postponed their 2020 seasons amid the coronavirus pandemic. Both could try to play football and other fall sports next spring.
As for Mr Biden, the presumptive Democratic presidential nominee, he is expected to announce his VP candidate pick this week ahead of next week's Democratic National Convention.
Read more about his not-so-shortlist of potential running mates here.
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