Vice President Kamala Harris' campaign said on Thursday that it did not use any materials that the FBI said Iranian hackers gathered from email accounts associated with former President Donald Trump's campaign and sent to President Joe Biden's campaign before he left the race.

Trump's campaign on Wednesday demanded more information from Harris' campaign including that it disclose the materials it received and whether it was used.

A Harris campaign official told ABC News that "the materials were not used." The campaign declined to comment on whether or not they would comply with the Trump campaign's request to disclose what they received.

Over the summer, Iranian hackers sent unsolicited emails to individuals associated with then-candidate Biden that "contained an excerpt taken from stolen, non-public material from former President Trump's campaign as text in the emails," according to information released by the FBI and other U.S. intelligence agencies on Wednesday.

The contents of those excerpts are not yet clear.

The FBI said there was no information indicating that the recipients of the information replied to the hackers' messages.

The White House said Biden only learned Wednesday about the Iranian hackers sending what the FBI called "stolen" information from the Trump campaign to individuals associated with his campaign.

"We learned about the statement yesterday, and the president has been made aware of it now," White House press secretary Karine Jean-Pierre said Thursday. "You've seen us take actions to hold accountable those who week to undermine confidence in our democracy, and we will continue to do so."

Harris' campaign said Wednesday that it has cooperated with law enforcement and the investigation into the messages and said it was "not aware of any material being sent directly to the campaign."

"A few individuals were targeted on their personal emails with what looked like a spam or phishing attempt," Harris campaign spokesperson Morgan Finkelstein said in a statement Wednesday.

Trump's campaign said hackers are interfering to help Harris and Biden "because they know President Trump will restore his tough sanctions and stand against their reign of terror."

Iran's Mission to the United Nations called the intelligence agencies' findings "fundamentally unfounded, and wholly inadmissible."

ABC News' Selina Wang, Jack Date and Luke Barr contributed to this report.