Taoiseach Micheál Martin has said there needs to be a meeting of “hearts and minds” before a border poll can take place.
The Fianna Fáil leader also said that Belfast needs to get rid of its peace walls.
Mr Martin told Newstalk FM’s The Hard Shoulder that he never thought there would be peace in Northern Ireland.
Mr Martin was part of Bertie Ahern’s government when the Good Friday Agreement was signed in 1998.
“My teenage years was bombs and bullets every day in the news, one atrocity after the other,” he added.
“I was a politician at the time. To be even a TD was a privilege.
“To be a government minister when the Good Friday Agreement happened, these were incredibly big changes.
“More changes will happen.
Mr Martin said there is a new “middle ground” emerging in Northern Ireland.
Asked about what lies ahead for Northern Ireland and Ireland and whether there might be a border poll or a united Ireland, Mr Martin said there needs to be a meeting of “hearts and minds”.
“If there’s an ease of relationship. If we can get rid of the peace walls. We still have too many peace walls in Belfast,” he added.
“Let’s get people more comfortable.
“A lot can happen in my lifetime but the exact precise nature of it…”
A poll published earlier this week suggested that people in Northern Ireland would vote to remain in the UK if a referendum was called in the present day.
Of those surveyed, 49% said they would vote to stay in the UK while 43% would support a united Ireland. The remainder were undecided.
The Lucid Talk poll, which had a sample size of 2,845 and a 2.5% margin of error, was conducted for BBC NI’s Spotlight programme.