Trump kept his answers short, taking shots at Acosta several times before moving to end the questioning.
Trump called him a "rude awful person", and after the incident, Acosta's access to the White House was revoked.
Watch Kimmel's segment on Sanders in the video above.
Research Director of the Tow Center for Digital Journalism at Columbia University Jonathan Albright and other observers later said the clip was likely doctored to make Acosta appear more aggressive than he actually was.
She called Acosta's behavior "absolutely unacceptable".
A few hours later, Acosta announced on Twitter that he was denied access to the White House and his "hard pass" had been revoked.
The incident comes amid an atmosphere of heightened hostility toward the media in the U.S. In late October, CNN was targeted with explosive devices sent through the mail. "She provided fraudulent accusations and cited an incident that never happened", CNN added in its statement. In a statement, the network labeled the decision to suspend Acosta's accreditation as "a threat to our democracy". He insulted Acosta, saying "I don't think he's a smart person but he's got a loud voice". "As visual journalists, we know that manipulating images is manipulating truth", said Whitney Shefte, president of the the White House News Photographers Association.
During a rare POTUS press conference on Wednesday the CNN reporter asked some questions Donald Trump didn't like.
Trump responded: "CNN should be ashamed of itself having you working for them".
Hostin, a lawyer, pointed out that, technically, if an assault took place, it would have been when the intern tried to grab the mic from Acosta, since the microphone is an extension of him. "You are a rude, awful person", Trump added.
"I'm not a fan of yours either". You are not the best.