Mr Trump was asked about comments made in the past by the former Australian prime minister describing him as a "traitor to the West" and "the most destructive president in history", in an interview with GB News presenter and former politician Nigel Farage.

"I don't know much about him; I heard he was a little bit nasty," Mr Trump said.

"I hear he's not the brightest bulb... if he's at all hostile, he will not be there long."

Mr Trump is set to return as the Republican presidential candidate in 2024 and is likely to face the incumbent Joe Biden.

Federal foreign minister Penny Wong backed Dr Rudd and told reporters on March 20 he was "a very effective ambassador".

Asked whether the government would retain him in the role should Mr Trump be re-elected, Senator Wong said "yes".

"He is a former prime minister, a former foreign minister, his experience and skills mean he will be able to work closely with whomever is elected by the American people," she said.

Meanwhile in question time Prime Minister Anthony Albanese slammed a question from the opposition about Dr Rudd's suitability for the role as a "cheap shot".

"One of the things I have never seen before in 28 years in the chamber is an attempt to politicise Australia's representative overseas in an important nation such as that," Mr Albanese said.

"When we engage with, particularly our AUKUS allies, the idea that we have a cheap shot question like that diminishes the opposition and says everything about why [Peter Dutton] is not fit to be prime minister of Australia."

Dr Rudd, who served as Australia's prime minister from 2007 to 2010, was appointed Ambassador to the US in March 2023.

He had previously been scathing of the former US president who he described as "nuts" in 2017.

In a 2020 tweet, Dr Rudd said Mr Trump was "the most destructive president in history".

"He drags America and democracy through the mud," he said.

"He thrives on fomenting, not healing, division.

"He abuses Christianity, church and bible to justify violence."

Earlier, an Australian Government spokesperson said Dr Rudd was "doing a good job" in the role.

Deputy Liberal leader Sussan Ley was asked about Mr Trump's comments on Sky News and said she did not comment on US domestic politics.

"I do want to say this; Kevin Rudd is our ambassador so we want him to do well because he represents Australia's national interests in the US," she said.

"I think members in the Albanese Government might reflect however that commenting on another country's domestic political situation is not a good idea."