President Joe Biden will blame Donald Trump for the US Capitol riot as he marks the anniversary of the attack on the seat of American democracy.
Speaking at Congress, Mr Biden will say his predecessor holds “singular responsibility” for the “chaos and carnage”, said spokeswoman Jen Psaki.
Investigators have so far arrested 725 suspects in connection with the attack.
Trump supporters stormed the building as Congress was meeting to certify Mr Biden’s presidential election victory.
Images of US lawmakers cowering from the mob in the gallery of the House of Representatives on that afternoon of 6 January 2021 shocked the world.
Mr Trump had urged protesters at a rally outside the White House shortly beforehand to “peacefully” march on Congress, but he also exhorted them to “fight” and stirred up the crowd with unsubstantiated claims of mass voter fraud in the election he had just lost.
The former president had planned to host a competing news conference on Thursday from his Mar-a-Lago resort home in Palm Beach, Florida. But he cancelled the event after aides reportedly warned of negative press coverage.
A spokesman for Mr Trump, Taylor Budowich, said it was “unsurprising” that Mr Biden would spend the day “trying to further divide our nation” in an attempt to distract voters from rising inflation and crime and coronavirus school closures.
President Biden – who rarely mentions his predecessor – will speak on Thursday morning in Statuary Hall, a section of the Capitol complex that was breached by rioters.
The White House press secretary said the president’s speech “will lay out the significance of what happened at the Capitol, and the singular responsibility President Trump has for the chaos and carnage that we saw”.
“He will forcibly push back on the lies spread by the former president – in an attempt to mislead the American people, and his own supporters, as well as distract from his role in what happened,” she added.
“President Biden has been clear-eyed about the threat the former president represents to our democracy,” Ms Psaki continued.
House Speaker Nancy Pelosi will preside over a moment of silence at noon on the chamber floor.
An inquiry into the riot is being conducted by a House committee, which is dominated by President Biden’s Democrats.
The panel is chasing phone records, visitor logs and other White House documents that could shed light on events leading up to the attack on Congress. They have issued legal summonses to members of Mr Trump’s inner circle.