Trump's remarks come on his platform Truth Social, where the US president claims that Biden used an autopen on 92 percent of all presidential orders issued in the White House.
He also claims that Biden was not present when the machine signed documents, and if Biden were to claim otherwise, he will be charged with perjury.
This is far from the first time Trump has attacked Biden for using an autopen. When he unveiled a presidential “hall of fame” at the White House in September, Biden’s portrait was replaced by a signing machine, and it still is.
In June, Trump also set up an investigation into Biden to try to prove his predecessor's "cognitive decline." One of the pieces of evidence was that Biden often used an autopen - a common tool for those who sign a lot of papers, not least presidents.
Trump has also previously claimed that Biden's pardons are not valid as a result of this tool, but analysts have pointed out that there is nothing in the US Constitution that stipulates that the president's pardons can be revoked, regardless of the choice of pen.
In June, Joe Biden denounced the allegations as “ridiculous” and “false.”
