Sinn Fein will be in government both north and south of the border by the end of May, Gerry Adams has said.
Gerry Adams is confident of electoral gains in the republic
The party leader's comments follow news that a general election will be held in the Republic of Ireland on 24 May.
Taoiseach Bertie Ahern has sought the formal dissolution of the Dail from Irish President Mary McAleese.
Mr Adams said his party was ready to take an active role. "We are going into this election in a stronger position than ever before," he said.
"We are contesting right across the state.
"By the time the election is over, we'll be in government here in the north and we're ready for government in the south, and we're looking a mandate."
News of the election date was only made public on Sunday even though unofficial campaigning has been in full swing in recent weeks.
Mr Ahern visited President McAleese's official residence Aras an Uachtarain at 0800 BST, hours before she was due to leave for a five-day visit to the US.
"President McAleese has dissolved the 29th Dail (parliament) this morning," her office said in a statement.
Posters began appearing hours after the election was called
Mr Ahern had kept his own Fianna Fail and opposition parties guessing about the possible date.
In power since 1997, Mr Ahern is seeking a third term in office.
Opinion polls have suggested a close race between Mr Ahern's Fianna Fail-Progressive Democrats coalition partnership and an alternative partnership of Fine Gael and Labour with possible Green participation.
The Irish Republic uses the Proportional Representation - Single Transferable Vote system, by which voters in multi-seat constituencies (electing three, four or five deputies each) are asked to rank their candidate preferences on a ballot paper.
If no one party secures enough seats to form a single party government, a coalition between parties is needed.
The Dail is made up of 166 members representing 41 constituencies.