President Joe Biden on Thursday accused his predecessor Donald Trump of spreading a “web of lies” to undermine U.S. democracy in a speech on the anniversary of the deadly Capitol attack by Trump supporters who tried to undo his 2020 election defeat.

Speaking at the white-domed building where rioters smashed windows, assaulted police and sent lawmakers fleeing for their lives on Jan. 6, 2021, Biden said Trump’s false claims that the election was stolen from him through widespread voting fraud could unravel the rule of law and subvert future elections.