EXCLUSIVE: Something may be holding Harry back from pursuing US citizenship, and it’s not the royal titles, an immigration lawyer has claimed.

If Prince Harry were to successfully pursue a US citizenship he would have to give up more than his royal titles, and it wouldn’t be worth it, with the “cons outweighing the pros,” says one immigration attorney.

Daily Express US spoke to Charlotte Slocombe, a partner at Fragomen, who says: “He may find it difficult to swear an oath of allegiance to the US in order to become a US citizen.”

Ms Slocombe explains why this could be troubling for the Duke: “Because he would need to declare on oath, that he ‘absolutely and entirely renounce [s] and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty, of whom or which [he has] heretofore been a subject or citizen.”

The oath of allegiance would come at the end of the naturalisation process, the first step would be to apply for a green card, and if approved, Harry would wait three years for the next step and during that time-frame his travel would be restricted.

Ms Slocombe believes it would be an “onerous route” for Harry and there would be “more cons than pros.”

The Invictus Games Foundation 10th Anniversary Service

He seems to be at his best when it comes to the Games, it’s been said (Image: Getty)

Ms Slocombe goes over some of the cons, saying: “The issue for both the Green Card and US citizenship, is that the concerns brought up by his public disclosures become far more difficult to waive, if applicable.”

She adds: “Also, he would need to renounce his royal title and be subject to worldwide tax filing (regardless of where he lived in the world). It would be an onerous route, with arguably more cons than pros.”

Prince Harry Attends Invictus Games Service at St Paul's Cathedral in London

Harry will be heading to Nigeria after his visit to the UK (Image: Getty)

In regards to the pros, Harry would be granted full freedoms of work, residence and ability to vote, according to Ms Slocombe.

Earlier this year, Harry appeared on Good Morning America, where he said he’s considered becoming a US citizen.

It seemed like he was saying it in passing, as part of the conversation with presenter Will Reeve, but more recently, Harry listed the US as his permanent residence in official paperwork, which has given the conversation new life.