US President Donald Trump has said his speech before last week's deadly Capitol riot, when he urged his supporters to march on Congress, was "totally appropriate".
Trump dismissed efforts by Democrats in Congress to impeach him for inciting insurrection as "ridiculous".
He leaves office on 20 January, when President-elect Joe Biden is sworn in.
Democrats in the House of Representatives say a vote to impeach the president will happen on Wednesday US local time.
If the vote in the House is carried, Trump will become the first president in US history to be impeached twice. However, the impeachment will only lead to his removal from office if a two-thirds majority votes in favour in the Senate.
That would need the assent of a substantial number of Republicans and so far, few have shown any willingness to vote against a president from their own party.
The House will vote first to ask Vice-President Mike Pence to invoke constitutional powers to remove Trump from office - an idea Pence is said to oppose.
What did Trump say in his speech?
During his speech at the rally in Washington on 6 January, Trump repeated his unsubstantiated claims of voter fraud during the 3 November presidential election and urged his supporters to march on Congress.
"We're going to walk down to the Capitol, and we're going to cheer on our brave senators and congressmen and women, and we're probably not going to be cheering so much for some of them, because you'll never take back our country with weakness. You have to show strength, and you have to be strong," he told the crowd of several thousand supporters.
He said Pence should have "the courage to do what he has to do", claiming without foundation that Pence had the constitutional power to overturn the votes which were being formally tallied in Congress that day.
Dozens of people have since been detained in connection with last week's violence.
The FBI is warning of armed protests in all 50 states by right-wing extremists ahead of Biden's inauguration. Up to 15,000 National Guard troops will be deployed in Washington DC for the event.
Impeachment moves causing anger, but 'I want no violence'
Trump, under pressure to resign, said there was tremendous anger about moves to impeach him but added he did not want violence.
"I want no violence," Trump told reporters as he left for a trip to the border wall in Alamo, Texas.
In his first remarks to reporters since 8 December, the embattled Republican president did not answer a question about whether he would resign.
He criticised impeachment moves by Democratic lawmakers.
"This impeachment is causing tremendous anger and they're doing it, and it's really a terrible thing that they're doing," Trump said. He added that the move to impeach him, on a charge of inciting insurrection over the Capitol attack, was a continuation of the "witch hunt" against him.
- BBC / Reuters