"You'll know my opinion on court packing when the election is over," Biden said during a campaign stop in Phoenix.
"It's a great question, and I don't blame you for asking. But you know, the moment I answer that question, the headline in every one of your papers will be on the answer to that question," he said.
Biden suggested that major media coverage of his stance on the Supreme Court would needlessly distract from "what's going on" in America.
The Democratic nominee has repeatedly refused to say whether he backs adding more seats to the court following the death of Justice Ruth Bader Ginsburg last month.
President Trump and Republicans have warned that Biden and other leading Democrats wish to "pack" the high court with liberal justices to offset an expected strengthened conservative majority that would result from the confirmation of Justice Amy Coney Barrett, Trump's pick to replace Ginsburg on the court.
"We are going to get a whole lot done, and as I've said, everything, everything is on the table," Sen. Minority Leader Charles Schumer (D-N.Y.) said earlier this month in response to Republicans' vows to confirm Barrett to the court before the Nov. 3 elections.
The Senate has scheduled confirmation hearings for Barrett for next week, with Republicans pushing to hold a vote on her nomination before the end of the month.
Biden similarly refused to give a definitive answer on Supreme Court seats during last week's debate against Trump.
"Whatever position I take in that, that'll become the issue," Biden said. "The issue is the American people should speak. You're voting now. Vote, and let your senators know how you feel."
Democratic vice presidential nominee Kamala Harris also refused to weigh in on packing the court when pressed by Vice President Pence during Wednesday night's debate. Pence admonished Harris:
"Once again you gave a non-answer, Joe Biden gave a non-answer. The American people deserve a straight answer. And if you haven't figured it out yet, the straight answer is they are going to pack the Supreme Court if they somehow win this election."
Comment: Biden's remark is a convenient dodge for a 'supremely' important question, the decision of which would alter the construction, definition and effect of the Supreme Court for generations to come. Likely he doesn't know the answer because no one has told him.
See also: The Left wants regime change and 'Court packing'