"Be proud of your patience, courage and sacrifice… Your Jihad up to this day has exposed America, the Zionist regime and its supporters, the United Nations and the hypocrites among the Islamic nation," Khamenei said.
"The Arab traitors should know that their fate will not be better than that of the Jews in the Battle of Ahzab," he said, alluding to one of Prophet Mohamed's wars.
"Nations are with the people and combatants of Gaza. Any government that acts contrary to this deepens the gap between itself and its nation.
"You are victorious this very day and by continuing this noble resistance you will bring the hopeless and anti-human enemy further defeat," the all powerful leader said.
More than 1,100 Palestinians have been killed since Israel launched an operation into Gaza late last month in retaliation for Hamas rocket attacks, according to Gaza medics.
Iran is a staunch supporter of the Islamist Hamas movement, which controls the Gaza Strip, and does not recognise its archfoe Israel.
In a letter to Saudi King Abdullah on Thursday Iranian President Mahmoud Ahmadinejad accused some Arab and Islamic states of complicity in "genocide" being carried out against Palestinians in Gaza.
