There seems to be 'some level' of cognitive impairment with US President Joe Biden, Ciara Kelly has said.
His fitness is being questioned after a special counsel investigation into the handling of classified documents said he portrayed himself as an "elderly man with a poor memory."
Robert Hur said President Biden had "wilfully retained and disclosed classified materials" after he was Vice President and when he was a "private citizen", and his actions "present serious risks to national security".
But the prosecutor said he chose not to bring criminal charges following a 15-month investigation because Mr Biden cooperated and would likely be difficult to convict.
Mr Biden (81) has said his memory is "fine."
Newstalk Breakfast host Ciara Kelly has said the issue is not about age.
"This is the President of the United States, and what's more he's about to run - we think - for the next presidency, it is extraordinary," she said.
"I don't care if Joe Biden is 95 if he's mentally competent, that makes no difference.
"We've all seen the gaffes where he stands up and he forgets who he's talking to, or he forgets where he is, it does seem that there is some level of cognitive impairment in Joe Biden.
"I find it extraordinary that a man who there's these kinds of questions hanging over, that's who they're going to field up against Trump".
'Hobson's choice'
Host Jonathan Healy said there are concerns around Joe Biden and his Republican rival Donald Trump.
"It's a Hobson's choice; what the American people are being presented with here is an 81-year-old who may or may not have issues with his memory and a 79-year-old - Trump - who also has shown some issues," he said.
"This is politics, this is senior stuff - and I mean that not in age terms.
"I think that if you have got any questions about your health, you simply should not be going forward for politics.
"It is incredible to think that out of the massive population of the United States, they cannot find somebody who would stand forward.
"I think the problem they have is that Joe Biden is forcing them into this because he is refusing to step aside.
"By refusing to step aside he is creating the Hobson's choice."
Ciara said while the two men are similar ages, Trump "hasn't made the kind of gaffes that he doesn't seem to know what he's talking about or where he is."