Sinn Fein's Martin McGuinness will meet the Queen next week and shake hands in an historic first for the Northern Ireland peace process, the party confirmed.
The Deputy First Minister at the Stormont executive will attend a cross border event in Belfast on Wednesday, which the President of Ireland, Michael D Higgins, will also attend.
Sinn Fein president Gerry Adams confirmed that his party's ruling executive had backed the planned meeting.
"This will understandably cause difficulties for some republicans and nationalists," Mr Adams said.
"Especially for those folks who suffered at the hands of British forces."
Video report by Tim Ewart
But the initial meeting and handshake between the Queen and the senior Sinn Fein representative is expected to take place in a private room at the beginning of the engagement, sources close to the planning have said.
The meeting is nevertheless being seen as a major milestone in efforts to normalise relations between nationalists and unionists.
Mr McGuinness, a former IRA member, was always the candidate to shake the Queen's hand but delicate talks have been going on for months to arrange a suitable venue and occasion.
Sinn Fein have stressed the meeting is not a celebration of the Jubilee.
Mr Adams defended the decision, saying: "We don't have to do it. We're doing it because it's the right thing to do, despite the fact that it will cause difficulties for our own folk.
"But it's good for Ireland. It's good for this process we're trying to develop. It's the right time and the right reason.
"After Martin McGuinness completes this engagement he will be as true, as staunch, as active a republican as he ever was."
Colin Parry, whose son Tim died in an IRA bomb blast in Warrington in 1993, has welcomed the historic meeting.
He said the handshake was a sign of how much progress was being made in the peace process.