Despite negotiations between Tehran and Washington that led to a nuclear deal and the lifting of sanctions, Khamenei has said there will be no further direct talks and no wider rapprochement.
“The people want neither a pro-government nor an anti-government parliament,” he said in Tehran.
“They want a courageous and devout parliament that knows its duties and is not intimidated by the United States.”
The remarks follow repeated warnings by Khamenei and other officials since the nuclear deal that Iran must guard against economic, social and cultural “infiltration” from the US.
The two countries broke off diplomatic relations soon after the Islamic revolution of 1979 which toppled a US-backed monarchy led by Shah Mohammad Reza Pahlavi.
Some 55 million Iranians are eligible to vote in Friday’s parliamentary election.
On the same day, they will elect the 88-member Assembly of Experts, the committee of clerics who monitor Khamenei’s work and will choose his successor if he dies during their eight-year term.
The polls will be a crucial indicator of the future direction Iranians want for their country, pitting moderate and reformist candidates supportive of President Hassan Rouhani against conservatives who have opposed him.