President Joe Biden savaged Donald Trump's "lies" and attempted

President Joe Biden savaged Donald Trump's "lies" and attempted to overturn the 2020 election, vowing on the first anniversary of the January 6 Capitol riot that he would let no one put a "dagger at the throat of democracy."

After largely ignoring Trump for a year, Biden took off the gloves, describing the Republican as a cheat whose ego wouldn't let him accept defeat and whose supporters almost shattered US democracy when they stormed Congress to prevent certification of the election.

It was a searing speech, signalling Biden's decision to abandon his previously cautious approach -- and it immediately prompted an equally bitter Republican backlash.

"This was an armed insurrection," Biden declared from Statuary Hall inside the Capitol, where a year ago thousands of people brandishing Trump flags trampled over police to invade the chamber, forcing lawmakers to flee for their lives.

"For the first time in our history, a president did not just lose an election. He tried to prevent the peaceful transfer of power," Biden said.

"I will allow no one to place a dagger at the throat of democracy."

Biden's voice filled with anger as he laid out the dangers facing a country that has long styled itself as leader of the free world.

"Are we going to be a nation that accepts political violence as a norm?" he asked.