"It's mortifying, it's embarrassing and it's dangerous," Biden said.
In a Fox News interview late on Monday (Aug. 31), Trump said an investigation was under way into alleged “thugs” who boarded a plane seeking to cause damage last week during the Republican Party convention, without providing details or evidence.
Asked for details by Fox News host Laura Ingraham, Trump said: "I'll tell you sometime, but it's under investigation right now."
On Tuesday, Trump told reporters that it was something told to him by an individual on the flight. Trump would not identify the person.
Asked to comment, White House spokeswoman Sarah Matthews did not address Trump's specific assertions but said he was referring to an investigation into possible financial backers of "organized riots."
The president, seeking re-election on a promise to restore "law and order," told Fox News the plane was "completely loaded with thugs wearing these dark uniforms, black uniforms with gear and this and that," adding, "Here were like seven people on the plane like this person and then a lot of people were on the plane to do big damage."