Sayid Muhammad Hussein Fadlallah was the spiritual guide of Lebanon's militant Hezbollah group during the 1980s.
Preaching at Friday prayers, he warned that new laws adopted in the United States following the Sept. 11 attacks constituted a danger and cited several cases of freezing or confiscating assets of Arabs and Muslims.
Fadlallah's words contrasted with those of business tycoon Prince al-Walid bin Talal of Saudi Arabia who Monday called for continuing investment in the United States.
The prince denied reports that Saudi investors had withdrawn some $200 billion from U.S. banks and said pulling out Arab and Islamic funds and stopping oil production would be ineffective.
Earlier this month, Fadlallah issued a fatwa in which he ruled it was forbidden to help America and its allies strike at the people of Iraq or allow them to control Iraq's economic resources, natural wealth and public policy.
The Muslims, Fadlallah said, should by themselves change their internal corrupt societies and end oppression in all Muslim countries.