The president added that he "doesn't have to" try to repair their relationship.
A bitter public feud between President Donald Trump and Elon Musk erupted on Thursday, with the Tesla billionaire agreeing to calls for Trump's impeachment while Trump suggested ending Musk's government contracts.
Musk showed some signs of softening his tone, but Trump on Friday told ABC News Musk was a "man who has lost his mind" and that he was "not particularly" interested in talking to him right now.
The spat began in part because of Musk's criticism of Trump's "One Big Beautiful Bill Act," a sweeping immigration and tax bill that would fund much of the president's domestic agenda.
President Donald Trump brought up his criticism about former President Joe Biden and the alleged use of an autopen to sign documents.
The president called it "the biggest scandal" of the last many years. Trump claimed he could tell it was an autopen. He said whoever was using it, it was illegal.
"Whoever used the autopen was the president," he added.
President Donald Trump commented further on his long-awaited call with Chinese President Xi Jinping earlier Thursday on trade.
Trump said he believed they "straightened out any complexity" regarding the agreement reached by top officials in Geneva last month. Over the past week, both the U.S. and China accused the other of violating the terms of the deal.
"I think we're in very good shape with China and the trade deal," Trump said. "We have a trade deal with China, as you know, but we were straightening out some of the points having to do mostly with rare earths, magnets and some other things."
President Donald Trump was asked if he spoke with Xi Jinping about allowing Chinese students to attend American schools.
The president said he wanted Chinese students as well as other international students to come to the U.S., but under more scrutiny.
"We want to have foreign students, but they have to be checked," he said.
Trump claimed Harvard did not give the administration its list of international students, but added that they are "starting to behave."
President Donald Trump was asked about his latest travel ban on specific countries around the world and why Egypt was not included.
The suspect in the Boulder, Colorado, attack was an Egyptian national and Trump cited the attack as a reason for his move.
"Egypt has been a country that we deal with. They have things under control. The countries we have, don't have things under control," Trump said of the nations affected by the ban.
