"I just think being from where we're from, we're placed in a very difficult position. I feel Northern Irish and obviously being from Northern Ireland, you have a connection to Ireland and a connection to the UK," McIlroy said.
The Co Down golfer said in a BBC documentary that he was enduring an uncomfortable battle of conscience.
"If I could and there was a Northern Irish team, then I'd play for Northern Ireland. I feel Northern Irish.
"Play for one side or the other – or not play at all because I may upset too many people – those are my three options I'm considering very carefully."
McIlroy has twice represented Ireland at the World Cup, but has since suggested a desire to switch allegiance for the Olympics in Brazil in three years' time. Complicating any such move is the fact that golf has traditionally been an all-Ireland sport.
When he argued last year that he felt "more British than Irish", his remarks stoked intense controversy, with RTE presenter Pat Kenny branding them "a stupid thing to say".
McIlroy subsequently issued a clarification, which stated: "I am a proud product of Irish golf. I am also a proud Ulsterman who grew up in Northern Ireland."
Asked in last night's programme if he regretted that episode, McIlroy said: "It was a moment, I don't want to say of weakness, but of frustration with it all. People tune in to watch me play on TV and feel like they are connected to me in some way.
"I don't want to repay them for their support by doing something that they wouldn't want me to do. When I do make a decision, it's going to be one that I've thought long and hard about, and one that I feel comfortable with."
The young golfer earned €11.9m on the golf course in 2012, which boosted his career prize money to €26.2m.
McIlroy splurged on an €8m six-bedroom home in the sunny Palm Beach Gardens in Florida, a few miles from Tiger Woods's estate, as a lucrative new contract from Nike worth US$200m (€152m) over 10 years kicked in on January 1.