Trump impeachment: Crucial 24 hours to determine US President's fate

President Donald Trump speaks during a campaign rally. Photo / AP

US Vice President Mike Pence has been given just one day to decide if he'll use the 25th amendment to get rid of Donald Trump once and for all.

After confirming that the House will be moving forward with legislation to impeach the outgoing President, House Speaker Nancy Pelosi said the House will first try to force Pence to remove the 74-year-old using the act.

In a letter to House Democrats, Pelosi said the action calls on Pence "to convene and mobilise the Cabinet to activate the 25th Amendment to declare the President incapable of executing the duties of his office".

If this happens, Pence would "immediately exercise powers as acting President".

"If we do not receive unanimous consent, this legislation is planned to be brought up on the Floor the following day," Pelosi said.

"We are calling on the Vice President to respond within 24 hours."

Vice President Mike Pence and Speaker of the House Nancy Pelosi during a joint session of Congress. Photo / AP

Pelosi said Trump represents an "imminent threat" to democracy, writing that "as the days go by, the horror of the ongoing assault on our democracy perpetrated by this President is intensified and so is the immediate need for action".

The articles of impeachment are expected to be introduced tomorrow, with a vote possibly happening as soon as the day after.

The impeachment announcement comes less than a week after pro-Trump rioters stormed the US Capitol building, resulting in five deaths.

Trump has been accused of inciting the attack, with leaders on both side of politics calling for him to be removed from office and held responsible for his part in the riot.