President Donald Trump said Thursday that former President Joe Biden’s use of an autopen to sign executive actions was “disrespectful to our country,” but suggested his predecessor may not have been aware of the use of his automated signature.

Trump has consistently raised concerns about Biden’s health decline and whether his aides were really in charge of the White House. On Wednesday, he backed an expanded Department of Justice investigation into the legality of Biden’s use of an autopen to sign documents, including pardons.