Though Harry is not eligible to vote in the election as he is a British citizen and member of the Royal Family, the former senior royal has voiced his support of the importance of voting.
Meghan Markle has been vocal about voting, however the duo have kept quiet about who they support.
But, Mr Trump perceived her words as partisan and said: “I’m not a fan of hers.”
The Duchess famously dubbed Mr Trump “divisive” and “misogynistic” back in 2016, only for the President to declare that the comments were “nasty” when he heard about them just before his state visit to the UK in June last year.
Days before he arrived, it was revealed that Meghan did not intend to attend any of his events because she was still on maternity leave — yet her absence still added to speculation of a Sussex boycott.
Harry then appeared to avoid talking to or being photographed with Mr Trump during a private lunch at Buckingham Palace days later, reports Express.
The Palace did not allow any reporters inside the lunch nor were the press given any details about what happened at the meal, so it is still not known if either men addressed Mr Trump’s claim that Meghan’s comments were “nasty”.
The Mail on Sunday’s royal editor Emily Andrews tweeted: “Prince Harry, who was also at the private lunch, noticeably hung back.“
He walked in with Ivanka (was he supposed to show her around the exhibition? Or maybe they sat next to each other at lunch) and then drifted off to talk to the Lord Chamberlain (the Earl Peel).”
CNN royal correspondent Victoria Arbiter speculated: “I would suggest that Harry’s inclusion in the Trump lunch tomorrow is more a courtesy to [Melania] to thank her for leading the US Invictus team to Toronto in 2017.
“Ultimately he’s there to support his grandmother but the royals’ job is to lay on the very best show and display of hospitality.
“MT [Melania Trump] led the US team to Toronto so now she’s on Harry’s turf it’s a way to return the gesture.”
Harry notably sat out the official state dinner that evening, which Kate Middleton and Prince William attended.
However, in an interview with Piers Morgan, the President said he spoke to Prince Harry and that he "congratulated him [on Archie’s birth] and I think he’s a terrific guy. The Royal Family is really nice.”
Mr Trump even dismantled claims that the Duke had avoided him, and said: “No, just the opposite. In fact, he spent a lot of time talking to Ivanka and talking to my family. I went up and he couldn’t have been nicer. I think he’s great.”
However, during two prank calls with a Greta Thunberg impersonator released in February this year — but recorded in December and January — Harry said the President had “blood on his hands” in relation to his response to the climate crisis.