Video report by ITV News Washington Correspondent Robert Moore
Donald Trump has called on Americans for "no violence", urging his supporters to "ease tensions and calm tempers" as voting on an article of impeachment for "incitement of insurrection" is under way.
US House of Representatives are currently voting on whether to impeach the president for a second time.
In a tweet-sized statement released from The White House, Mr Trump said: "In light of reports of more demonstrations, I urge that there must be NO violence, NO lawbreaking and NO vandalism of any kind."
"That is not what I stand for and it is not what America stands for. I call on ALL Americans to help ease tensions and calm tempers. Thank You."
Congress are voting on impeaching US President on the article of impeachment, for "incitement of insurrection," urging his supporters to march on the U.S. Capitol last week, resulting in violent clashes which left five dead.
Mr Trump is likely to become the first US president in history to be impeached twice as the article of impeachment is expected to pass in the Democratic-controlled House.
If the House impeaches President Donald Trump, a Senate trial on whether to convict him of inciting insurrection seems will have to wait until President-elect Joe Biden is inaugurated, according to a spokesman for Senate Majority Leader Mitch McConnell.
The spokesman said aides to the Kentucky Republican have told Senate Minority Leader Chuck Schumer’s staff that McConnell won’t agree to invoke powers calling senators into emergency session.
That means the Senate almost certainly won’t meet again until 19 January - the day before Biden’s inauguration.
At least seven Republicans have publicly said they will join Democrats in voting to remove Trump from office.
NBC reporter Leigh Ann Caldwell has said the House Democrat majority leader, Steny Hoyer, told her that impeachment would be sent to the Senate immediately should it pass.
However, 100 senators would have to agree to return to work, otherwise it would not get heard until next Tuesday.
Speaker of the House, Nancy Pelosi, said Trump has "repeatedly lied" about the outcome of November's 2020 election.
In a House Speech, Ms Pelosi said members of Congress and the country as a whole "experienced the insurrection that violated the sanctity of the people’s Capitol and attempted to overturn the duly recorded will of the American people".
Ms Pelosi said Trump is a "clear and present danger to the country we all know and love", before adding, "he can feel his power slipping away."
"We know that the president of the United States incited this insurrection this armed rebellion against our common country. He must go," she added.
House Republican leader Kevin McCarthy said Trump "bears responsibility" for last week's storming of the Capitol by his supporters.
McCarthy, a close Trump ally, says the president "should have immediately denounced the mob when he saw what was unfolding.”
But McCarthy also said he believes it would be a mistake to impeach Trump in such a short time frame.
He said: "A vote to impeach would further divide this nation, a vote to impeach will further fan the flames, the partisan division."
ITV News Washington Correspondent Emma Murphy reports from Washington DC saying: "This is not what they are used to seeing in this city, we've got the national guard and the police on the streets - you can't move without showing your ID."
Washington Correspondent Emma Murphy continues: "There is a real fear about security in this city and across the country."
She adds that this fear will also be felt with Republicans who may wish to vote against Trump but are genuinely scared to do so.
She said: "Donald Trump was impeached previously and that was done simply by the Democrats they didn't have the support of Republicans.
"But this time they have five very very senior Republicans have come out and said that this attempt to impeach is something they can support.
"It is incredibly significant because it just shows just what horror there is of what went on last week.
"We understand there is a great deal of concern against Republicans as they decide what to do as they feel genuinely fearful for their own safety if they decide to stand up and say they will impeach this president."