US politician Brendan Boyle, who serves as a member of Congress for Pennsylvania, has said any win in the presidential election could come down to three key states.
As counting continues in the election, Mr Boyle told Newstalk Breakfast the race is too close to call.
But that his state of Pennsylvania could be the clincher.
"I think at this point certainly it will come down to Michigan, Wisconsin, Pennsylvania.
"And it looks like best two out of three."
"That whichever candidate is able to carry at least two of the three, will win this election.
"That's assuming that Joe Biden does win Arizona - one of the [TV] networks had already called it for him, he's up by a pretty good margin there.
"But it still hasn't been put to bed."
"It also assumes that Donald Trump holds on in Georgia - still some doubt about that, given how much of the vote is left to counted in Atlanta."
"But be that as it may, I would still fully expect that it'll be coming down to Pennsylvania, Michigan, Wisconsin - which in many ways is right to where we thought this race would be after 2016."
'Bulk of the vote'
"So this is pretty unprecedented, the fact that for the first time ever we've had vote by mail in Pennsylvania.
"Disproportionally, we know Democrats have taken advantage of it - and disproportionately the votes out of Philadelphia and the Philadelphia suburbs tend to be Democratic.
"So the bulk of the vote that's left to be counted is by registered Democrats.
"So even though Donald Trump at this moment is showing a double-digit lead in Pennsylvania, the reality is there are still some 300,000 votes in Philadelphia that haven't been [counted] - at least 80% of which should go for Joe Biden."
"At this point, I would just say it's too early call".
'America may not recover'
It comes as Mr Trump hit out at voting "fraud" without any evidence, claiming victory before all results have been announced.
In an address to the nation from the White House, he vowed to take his fight to the Supreme Court because he wants "the law to be used in a proper manner".
"We will win this and as far as I'm concerned we already have won it," Mr Trump added - though 10 states are yet to declare and result remains on a knife-edge.
Earlier, his Democrat challenger Joe Biden said people should "keep the faith".
Addressing Americans at a drive-in rally he likely hoped would have been the site of a victory speech in Delaware, Mr Biden said people should "keep the faith" while vote counting continues.
"It may take a little longer," he warned.
While president of Irish-American lobby group the Irish National Caucus has said if Mr Trump wins another four year term as US president, America "may not recover for another 100 years".
Father Sean McManus told Newstalk Breakfast: "If Trump wins another four years, America is in profoundly serious trouble and may not recover for another 100 years.
"And I don't know if people at home in Ireland, and Dublin, realise the seriousness of it."