Mr Trump was participating in a roundtable discussion with the "Latinos for Trump Coalition" in Las Vegas when he made the comment.
The president stated — incorrectly — that Mr Biden favoured "after-term abortion, which is basically baby execution."
Mr Biden's voting record has been historically conservative with regard to abortion. Throughout the 1970's and 1980's Mr Biden consistently voted to restrict expansions to Roe V. Wade.
In recent years, Mr Biden appears to have softened somewhat on his stance. He has promised to codify Roe V. Wade into federal law and has spoken out against the Hyde Amendment, though only doing so after being pressured by other Democrats.
The attack from Mr Trump is the latest attempt from the president to paint Mr Biden as extremely far left. Mr Biden's voting record does not support the president’s claims.
During his first term, Mr Trump has introduced policies that make it harder to get an abortion. The president has cut federal funding for organisations that provide abortions or refer patients to abortion clinics.
A poll by Pew Research in August found that some 46 percent of Mr Trump’s supporters say abortion is a “very important” factor in deciding how they will vote in November, compared to 35 percent of Mr Biden’s supporters.