Mr Trump last week made history as the only US president to be impeached twice and is due to face a Senate trial to decide if he will be convicted of inciting an insurrection.

Mr Morrison said the January 7 riot - which led to the deaths of five people - was deeply distressing.

"It was disappointing, very disappointing, that things were allowed to get to that stage," he told 2GB radio on Monday.

"The things that were said that had encouraged others to come to the Capitol and engage in that way, were incredibly disappointing, very disappointing."

"America is very important to Australia and very important to this part of the world, and it's important we see them come together in that way and we'll be doing everything we can to support that and encourage that outcome."

Mr Morrison said he spoke to Joe Biden soon after he "clearly won" the election and was unlikely to do so again until after the incoming president's inauguration this week.

"America's going through a very terrible time at the moment but (we are) looking forward to the country uniting and moving on from these terrible last few months and particularly these last few weeks."

If Mr Trump is convicted on the impeachment charges he could be disqualified from seeking another run for the presidency in 2024.

Mr Biden will be inaugurated as 46th US president in Washington DC early Thursday morning, Australian time.

Australian Associated Press