Pelosi confirms Trump impeachment

House Speaker Nancy Pelosi has confirmed that the House will be moving forward with legislation to impeach President Donald Trump, saying the 74-year-old represents an "imminent threat" to democracy.

She made the announcement in a letter to House Democrats late on Sunday.

"In protecting our Constitution and our Democracy, we will act with urgency, because this President represents an imminent threat to both," Ms Pelosi wrote.

"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 on Monday, with a vote possibly happening as soon as Tuesday.

Ms Pelosi said before the Tuesday vote the House will first try to force Vice President Mike Pence to remove Mr Trump as president using the 25th Amendment.

She said the action calls on Mr Pence "to convene and mobilize the Cabinet to activate the 25th Amendment to declare the President incapable of executing the duties of his office."

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