Bolstered by support from his deputy Mike Pence who opposed ousting the US president, Donald Trump denied responsibility on January 12 for an assault on Congress by his supporters but now faces an all-but-certain second impeachment effort.

With Republican backing for Trump eroding in the final days of his presidency, Pence served as an anchor, ruling out calls by Democrats to invoke the 25th Amendment in order to remove the president from office.

“I do not believe that such a course of action is in the best interest of our nation,” Pence wrote in a letter to House Speaker Nancy Pelosi shortly before the House was set to vote on a measure calling on Pence to use the amendment to strip Trump of power.

With that effort dead, Pelosi quickly announced her managers for the impeachment debate, the strongest signal yet that she is going ahead with a move to make Trump the first president in US history to be impeached for a second time.

An impeachment vote in the House of Representatives is expected on January 13.

The single charge of “incitement of insurrection” – over his January 6 speech in which he claimed he was the real winner of the November election, then urged supporters to march on Congress and “fight” – is all but sure to get majority support.

Earlier Trump travelled to Alamo, Texas, and although he urged “peace and calm” during a visit to his Mexico-US border wall, his overall message was of refusal to take blame.

The crowd attacked the Capitol, fighting with police, ransacking offices, and briefly forcing terrified lawmakers – and Pence – to abandon a session certifying Democrat Joe Biden’s election victory.

A defiant Trump insisted that “everybody” thought his speech was “totally appropriate”.

Trump dubbed his likely impeachment a “continuation of the greatest witch hunt in the history of politics”.

And he warned that while “you have to always avoid violence”, his supporters are furious.

“I’ve never seen such anger,” he said.

Democrats are all but sure to pass impeachment in the House.

It seemed unlikely that the Republican-controlled Senate would be called into an emergency session to put Trump on trial before his term runs out on January 20.