"He hasn't done anything, really. I think it's just a joke. Hopefully it will be over relatively soon," Diller said. "It inexplicably began and it will inexplicably end."
The comment came in a wide-ranging interview with CNBC's Julia Boorstin at the Allen & Co. Sun Valley conference in Idaho. Diller, whose brands include Match.com, Dictionary.com and Vimeo, also discussed net neutrality and immigration. Diller is involved in the travel industry through his position as chairman of Expedia.
Diller has been critical of Trump in the past, calling him an "evil miracle," although he said there are many smart people in the administration. Diller has been friendly with Trump family members Ivanka Trump and Jared Kushner over the years, he said, but he added that he probably wouldn't bring up issues from the current administration with them.
"I can't blame them for the current situation," Diller said. "What would be the point of bringing it up to someone who has no curiosity, doesn't listen, etc.? Why would anybody bother?"
(Kushner has been vocal on technology issues, coordinating meetings with some of the top CEOs in the sector. Chelsea Clinton, daughter of Trump's election opponent Hillary Clinton, is a member of the boards of IAC and Expedia.)
One of Diller's main issues with the administration is around immigration. Diller said that Trivago has been having "the easiest time" recruiting U.S. employees to come to Germany amid proposals to tighten U.S. immigration. Trump has focused on an "America first" agenda when it comes to skilled labor and has proposed "extreme vetting" of immigrants from countries that the president says are known for terrorism.
"We're going to lose talent, rather than importing talent that we always need," Diller said. "The immigration policies are reprehensible."
Diller said that he does support tax reform, especially reduced taxes on the repatriation of foreign earnings.
"I hope it happens, I hoped it would happen during the Obama administration," Diller said. "But I don't know, I think this administration will have difficulty getting anything done."
Another issue that will affect Diller's companies is net neutrality protections. While all content is currently treated equally by service providers, new FCC Chair Ajit Pai has asserted that he believes these protections go too far.
Diller said that rolling back protections of net neutrality could threaten the "magic" of the internet. IAC is one of many companies rallying against the regulation changes.
"I'm confident that we will have net neutrality," Diller said. "But I'm only confident to the level that just ordinary people don't recognize that their free communications are going to be in danger."
One of those communication tools is Snapchat, which has mounted an uneasy transition into the public market in the past few months. While Diller doesn't know if Snap can grab the third place spot in the race for online ad dollars (behind Facebook and Google), he said it's still among the top companies out there.
"People like Snapchat," Diller said. "I think that there's a lot of hype. I don't think any IPO is at all relevant until three, five years after, other than the people who sell at the beginning, or buy at the beginning and hold. So I think time will tell. But I think Evan Spiegel, who runs it, is brilliant."
The White House did not respond to a request for comment.
Disclosure: CNBC parent NBCUniversal is an investor in Snap.