Khamenei was speaking at a three-day conference, dubbed International Conference of Holy Qods and Support for the Rights of the Palestinian Nation, being held for the third year in Tehran.
He said jihad was not only taking place in occupied Palestine and Qods (Jerusalem) but all over the Islamic world.
Hard-line President Mahmoud Ahmadinejad, who recently called for Israel to be wiped off the map, also attended and addressed the conference.
Other participants included Majlis (Parliament) Speaker Gholam-Ali Haddad-Adel and Judiciary Chief Ayatollah Mahmoud Hashemi Shahroudi.
State-run media have given widespread coverage to the event in the days leading to it. The official news agency has reported that some 600 foreign officials including 20 parliament speakers from Syria, Lebanon, Algeria, Sudan, Indonesia, Uganda, Cameroon, Congo, Zimbabwe, Sierra Leon, Cuba, Comoros, Madagascar, Malaysia, Qatar, Mauritania, Mauritius, the Seychelles, Sri Lanka and Guinea would take part in the event.
