Trying to get anything done with Donald Trump's administration was like "talking to a brick wall", according to the former New Zealand ambassador to the United States.
Tim Groser told The AM Show he didn't want to "mince his words".
"We could make no progress at all."
But with President Joe Biden in charge, Groser says he hopes things will be easier.
He says the feeling after Biden's election win was "a collective sigh of relief".
"Everyone wants to see a more constructive America in world affairs and I think that's what we're going to see.
"The quality of the people [Biden] is putting around him are just stellar so I am hoping that when they can turn their attention to the issues that are of long term concern to us will get some real engagement with the administration."
President Biden was inaugurated on Thursday morning after a lengthy and contentious election process which saw former President Donald Trump wreak havoc by claiming it was rigged.
The false claims of a rigged election culminated in chaos when Trump supporters stormed the US Capitol in a riot which resulted in the deaths of five people.