The DUP has attacked Sinn Féin over a meeting with Palestinian militant group Hamas in Turkey at the weekend.
A delegation to Istanbul was headed by Sinn Féin's national chairperson Declan Kearney who met one of the main Hamas leaders, Musa Abu Marzouk among others.
The DUP warned that Sinn Féin had regularly tried to use the international stage to justify its past violence. MEP Diane Dodds also said the example of Northern Ireland showed that terrorism could not win.
But Sinn Féin insisted its support of the right of the Palestinian people to self-determination would not waver.
Republican contacts with groups in the Middle East stretch back decades, with the party's MEP Martina Anderson also due to visit the central West Bank city of Ramallah later this week.
In 2005, Sinn Féin leader Gerry Adams met members of Hamas - the largest militant group in the region - in the Palestinian parliament and laid a wreath at the tomb of the former president Yasser Arafat.
Mrs Dodds said: "Sinn Féin have regularly sought to use the international stage to wrongly glorify their own past. The Northern Ireland example highlights that terrorism does not win."
But Mr Kearney said Sinn Féin had outlined its experience of the Irish peace process to Hamas. "We shared our view that Palestinian national, political and civic unity should be central to future political progress and that inclusive negotiations are essential to securing a peaceful, democratic, political agreement," he said. "The unremitting blanket repression by the Israeli state against Palestinian citizens in both Gaza and the West Bank is an international scandal."