"The decision by the Israeli authorities to refuse me entry into Gaza is deeply disappointing," Adams, whose party is most closely linked to the Irish Republican Army (IRA), said in a statement Friday.
"My purpose on this visit has been to listen. Primarily I am here to learn," Adams continued, adding, "When asked I have also outlined the broad strategic approach Sinn Fein took to the Irish Peace Process."
Sinn Fein is the second-largest political party in Northern Ireland and the fourth-largest in the Republic of Ireland. Allegations of Sinn Fein's links with the IRA, a paramilitary group fighting against Northern Ireland's union with the United Kingdom, have been repeatedly denied by party officials. Adams has last visited Gaza in 2009 on a two-day trip.
The latest wave of violence erupted in Gaza and the West Bank on July 8, with heavy Israeli bombardment that resulted in 2,100 deaths. The United Nations estimated there were 1,500 civilian casualties, most of them occurring in Gaza.