The United States Homeland Security chief says anyone who brands US President Donald Trump a racist would also have to deem Australian Prime Minister Malcolm Turnbull one too.

Kirstjen Nielsen on Sunday said the merit-based immigration system Mr Trump wanted to introduce was the "exact" same as what Australia and Canada had.

Mr Trump had been condemned in the US and across the globe for reportedly labelling Haiti, El Salvador and African countries as s***holes and suggesting the US should accept more people from countries such as Norway.

"I take a little bit of offence to the comments and suggestions that the president is racist," Ms Nielsen said during an interview on Fox News Sunday in the US.

Ms Nielsen says what Mr Trump is looking at is the same as the merit-based system used in Australia and Canada.

"I'm sure that we are not, any of us, suggesting that Canada and Australia and their leaders are racists," she said.

When interviewer Chris Wallace responded Mr Trump "seems to be suggesting you'd rather have a janitor from Norway than a doctor from Haiti", Ms Nielsen disagreed.

"I think what he's trying to do is move away from a quota-based system, whether that's a quota of underrepresented countries or a quota of Norway, for example," Ms Nielsen said.

"I think what he's trying to say is we need to look at the individual and ensure that we look at those who can bring merit to our country."

The Homeland Security secretary was in the Oval Office on Thursday when Mr Trump allegedly uttered "s***hole" in front of Democrat and Republican members of Congress while discussing a potential bipartisan immigration deal.

Mr Trump denied making the comment.

Ms Nielsen, like the Republicans in the Oval Office, refused to confirm or deny Mr Trump's use of "s***hole".

"I don't recall him saying that exact phrase," Ms Nielsen said.

Republican Senator Lindsay Graham did release a statement saying he confronted Mr Trump about his disparaging remarks, although he did not explicitly confirm the president used "s***hole".

Democratic Senator Dick Durbin, a key negotiator in immigration talks, told reporters the president used the word.