The president’s eldest son was called out by a fact-checker on Tuesday for promoting the fake clip, which attempted to show Mr Biden lost and confused on stage at an event on 16 January.
“Yikes. If he was a Republican the 25th amendment talk would be trending and rightfully so,” the 43-year-old wrote as a caption to the video, which has since amassed 64,000 likes.
Nonprofit fact-checker Politifact reported on Tuesday that the video had in fact been edited to promote a false narrative.
The original footage from the event, during which Mr Biden announced members of his White House science team, shows Mr Biden making some closing remarks alongside Vice-President-elect Kamala Harris.
Another angle also shows that when Mr Biden leaves the podium and stands at the table momentarily, he’s waiting for other people to leave the stage.
On Twitter, the doctored video has gained more than three million views, and Politifact reported that similar clips had also been circulating on Facebook.
Twitter flagged the video as “manipulated media”, but users were apparently still able to retweet and share the video. Facebook also flagged the content in an attempt to stem the spread of misinformation.
Politifact pointed to a misinformation guide by The Washington Post to define the video as manipulated by “omission.”
Omission involves “editing out large portions from a video and presenting it as a complete narrative, despite missing key elements, is a technique used to skew reality," the newspaper says.
Yikes. If he was a Republican the 25th amendment talk would be trending and rightfully so. pic.twitter.com/ohKjOSdoJI
— Donald Trump Jr. (@DonaldJTrumpJr) January 17, 2021
Some social media users were quick to call out the president’s son for promotion of the false narrative, saying: “the outgoing president's 43-year old son is spreading manipulated media online.”
Others called on Twitter to do more to remove the video, which continued to gain traction on social media platforms, including whistleblower Shahmir Sanni who tweeted: “Hi @Twitter this one needs to be banned too.”
The Trump campaign has long attempted to paint Mr Biden as senile and incompetent in an attempt to undermine his bid for president and leadership.
Donald Trump Jr has also made several false claims about Mr Biden and the 2020 election in support of his father’s bid to remain in power.
But despite Mr Trump and many of his family's best efforts, Mr Biden will be inaugurated as president on 20 January 2021 to become the 46th president of the United States.
The president and first lady Melania Trump are breaking the tradition of meeting the incoming first family greeted by White House and will not attend the inauguration on Wednesday.