Israel has banned Irish politician Gerry Adams from visiting the Gaza Strip.
Sinn Fein president Adams had planned to visit the embattled area during a three-day long trip to the reason.
The Irish nationalist said he was "disappointed" by the decision, for which Israel had provided no explanation, Adams said.
Adams met with Palestinian president Mahmoud Abbas during a previous visit to the embattled region.
He previously has called for Palestine to be granted statehood.
Adams said: ""The decision by the Israeli authorities to refuse me entry into Gaza is deeply disappointing, particularly as I was able to spend two days there in 2009.
Preventing me from travelling to a Gaza and talking to those citizens who have survived three Israeli assaults in the last decade, and who are besieged and in need of massive aid to rebuild their shattered economy and society, runs contrary to the needs of a peace process and is very unhelpful.
"I raised the recognition of a Palestinian state with the Taoiseach this week in the Dáil and I intend to continue to raise it. The people of Palestine have the right to national statehood.
"It's not an issue for negotiation. It is a principle and a right. The international community has an obligation to support this and to uphold international law."
A spokesman at the Israeli embassy could not be reached for comment.
Adams was a key actor in the peace process in Northern Ireland, which saw an IRA ceasefire in 1994, leading to talks chaired by Senator George Mitchell that concluded with the Belfast Agreement, signed on Good Friday 1998. This agreement paved the way for the end of the IRA's armed campaign in 2005 and a power-sharing government in Northern Ireland.