A high-level delegation from Hamas arrived in Tehran early on Sunday as part of a regional push to reinforce support for the Palestinian group after the Israeli invasion of Gaza, a Hamas official said.
The delegation, headed by Hamas leader Khaled Meshaal, will later meet Iran's Supreme Leader, Ayatollah Ali Khamenei, and President Mahmoud Ahmadinejad, Izzat al-Rishq told Reuters by telephone from Tehran.
Hamas was in close contact with Iran, its main backer along with Syria, during the 22-day Israeli offensive against Gaza, which was halted last month, with the two sides declaring separate ceasefires.
Hamas views the war as resulting in regional diplomatic gains for the group, with Turkey criticising Israel and Qatar convening a high profile meeting with the participation of Hamas that supported Hamas's objectives.
Meshaal visited Qatar last week. Five other Hamas politburo members are accompanying Meshaal on the visit to Tehran.
Hamas said it would intensify its post war diplomatic efforts to lift the Israeli blockade on the Gaza Strip, imposed with the help of Egypt.
The group has kept a line open with Cairo, which is mediating a deal for a more solid truce that tries to meet Israel's demands for stopping arms flows into Gaza and Hamas's demands for lifting the blockade.
Hamas regards the blockade, which damaged Gaza's economy and further impoverished the majority of the territory's population, as a form of illegal collective punishments and cited it as a reason for not renewing a previous ceasefire for Israel in December.