Minister Jack Chambers is insisting a controversial religious ceremony to mark the partition of Ireland is not a celebration or commemoration.
The Junior Minister and the Foreign Affairs Minister Simon Coveney will attend the event in Armagh today.
President Michael D Higgins declined an invitation to the service.
Britain's Queen Elizabeth also won't be in attendance, due to ill health.
But despite some controversy, Jack Chambers says if the Government is serious about promoting peace, it has to listen to different perspectives.
"I think it's important to set out what the event is and what it isn't," he said.
"It's about peace, it's about healing".
Meanwhile, Sinn Fein is the only political party in the North not attending the event.
DUP Brexit Spokesperson Sammy Wilson believes Sinn Fein are making the wrong decision.
"We get all this stuff from Sinn Fein all the time that they want a shared society, that they want to have reconciliation."
"Every time that there's an occasion to show that they mean what they say they refuse to do so."