New Hampshire Gov. Chris Sununu said Thursday that he was aware of Biden's obvious physical and mental decline as early as February.
Sununu specifically cited a meeting he had with the president and fellow governors, where Biden was struggling during his conversations.
'Physically, you could see, he does the shuffling thing ... mentally, when you ask him a question, is it clear, he is trying his best to regurgitate what other people told him...' he said.
Sununu spoke about Biden during a virtual interview with Politico reporter Eugene Daniels at the CNN/Politico grill at the Republican National Convention in Milwaukee, Wisconsin.
News of Democrats pressuring Biden to exit the race is a constant topic of conversation at the convention.
New Hampshire Gov. Chris Sununu relished telling reporters he had warned them about Biden for months
Sununu appeared to relish his interview with reporters, reminding them that he had been predicting for months that Biden would not be the nominee.
'It's real. It's happening,' he said predicting that once the Republican convention was over the media focus would be solely on Biden.
The New Hampshire governor cited Biden's low whispering in speeches and conversations and admitted that governors struggled to understand him.
'Sometimes he's just not in the conversation that you're trying to have,' he said.
Sununu cited a conversation that Biden had with Montana governor Greg Gianforte about the leaves on trees changing colors because of climate change.
'As a person I feel bad for the guy,' he said, about Biden adding that Biden's family and staff was not serving him well. 'Running for president is not what this guy should be doing right now.'
President Joe Biden is greeted by Gov. Chris Sununu, R-N.H., as he arrives on Air Force One at Manchester-Boston Regional Airport
President Joe Biden waves as he walks down the steps of Air Force One at Dover Air Force Base in Delaware,
'When you're dealing with issues of dementia or getting old or whatever this might be, it's clear to me that it was getting worse and worse and worse,' he said.
He blamed Democrats for not accepting the idea that Biden would not be fit to run for reelection.
Biden, Sununu said, had to make a 'legacy decision' to make.
'He can be the Democrat that everyone remembers for moving Trump off the ballot in 2020, or the Democrat that everyone remembers that overstayed his welcome and handed it back to Republicans — which is fine by me,' he said.
He predicted that Vice President Kamala Harris would be the eventual nominee and encouraged Republicans to start polling on her to prepare for a campaign shift.
Sununu also mocked reporters who were acting surprised about Biden's rapid physical and mental decline.
'Guys, this is not a new story, this is not a surprise ... what have you been watching for the past two or three years? Everyone in America sees it,' he said.