The White House first defended the post, then deleted it early on Friday, 12 hours after it appeared.
Trump, asked by reporters later in the day if he condemned it, replied, "Of course I do."
A White House official said that "a White House staffer erroneously made the post" and it had been taken down.
Trump said he looked at the "first part" of the video but not the final scene that drew criticism.
"I didn't see the whole thing," Trump said.
"I looked at the first part, and it was really about voter fraud in the machines, how crooked it is, how disgusting it is. Then I gave it to the people. Generally, they look at the whole thing. But I guess somebody didn't."
A Trump adviser previously told Reuters the president had not seen the video before it was posted late on Thursday and ordered it taken down once he had.
Both officials declined to be named. The White House did not respond to a question about the staffer's identity. Only a few senior aides have direct access to Trump's social media account, according to the Trump adviser.
White House spokeswoman Karoline Leavitt hours earlier had defended the post, describing the wave of negative reactions as "fake outrage".
The minute-long video shared on Trump's Truth Social network amplified false claims that his 2020 election defeat was the result of fraud. Spliced into the video near its end was a brief, and apparently AI-generated, clip of dancing primates superimposed with the Obamas' heads.
A spokesperson for the Obamas declined to comment.
Trump has a history of sharing racist rhetoric. He long promoted the false conspiracy theory that Obama, the president from 2009 to 2017, was not born in the United States. Speaking at a prayer breakfast on Thursday, Trump said Obama "was very bad" and a "terrible divider of our country."
The post drew bipartisan criticism, including from Republican Senator Tim Scott, a close Trump ally who is Black.
"Praying it was fake because it's the most racist thing I've seen out of this White House," Scott said on X.
"The President should remove it."
Before the post was deleted, Leavitt said it was "from an internet meme video depicting President Trump as the King of the Jungle and Democrats as characters from the Lion King." Trump's clip included a song used in that Disney musical.
White supremacists have for centuries depicted people of African ancestry as monkeys or apes as part of campaigns to dehumanise and dominate Black populations.
"Let it haunt Trump and his racist followers that future Americans will embrace the Obamas as beloved figures while studying him as a stain on our history," said Ben Rhodes, a former Obama aide, on X.
Trump, serving his second term in office, has long used social media to unveil policy, weigh in on issues and share fan-generated content to his nearly 12 million followers on Truth Social, a platform owned by his Trump Media & Technology Group.
with AP
