Ms. O’Malley Dillon also wrote that Mr. Biden was committed to debating Mr. Trump on Sept. 29, Oct. 15, and Oct. 22, and that his yet-to-be-selected running mate would take part in the vice-presidential debate scheduled for Oct. 7.
“Our position is straightforward and clear: Joe Biden will accept the Commission’s debates, on the Commission’s dates, under the Commission’s established format and the Commission’s independent choice of moderators,” Ms. O’Malley Dillon said in the letter, which was obtained by The New York Times. “Donald Trump and Mike Pence should do the same.”
“Any ‘debate proposals’ in lieu of that are just an effort to change the subject, avoid debates, or create a distracting ‘debate about debates,’” she added.
The details of the letter were first reported by The Washington Post.
The letter came four days after The Times reported that top aides to Mr. Trump had held an online meeting with officials overseeing the debates, in which they pushed for a fourth debate between Mr. Trump and Mr. Biden and argued that the events should take place sooner than planned in order to accommodate voters wishing to cast their ballots early. (Mr. Trump, meanwhile, has repeatedly and falsely claimed that mail-in voting is rife with fraud.)
Rudolph W. Giuliani, Mr. Trump’s personal lawyer, was in the meeting and also proposed a system allowing both campaigns to recommend a set number of moderators and then strike some of them from their opponent’s lists until an agreement was reached.
In her letter, Ms. O’Malley Dillon noted that the Trump campaign’s position was a shift from months earlier, when the president’s advisers were discussing whether Mr. Trump would take part in debates sponsored by the commission at all. “The Trump position seems to be saying that he will debate if he can pick the moderators,” she wrote.
The commission, which has produced the general election debates since the 1988 campaign, typically spends months negotiating the details with representatives for the candidates. The group did not respond to a request for comment.