TEHRAN — In a rare effort to reach out to the West, Iran’s supreme leader released a letter to youngsters in the United States and Europe imploring them to learn about Islam from original sources and not, as he said in a later posting on Twitter, have it “introduced to you by prejudices.”

The Iranian leader, Ayatollah Ali Khamenei, says in the tweet and in the letter, published on his website, that he does not “insist that you accept my or any particular reading of Islam,” but wants to address young people after the attacks in Paris by militants who said they acted in the name of Islam.

“The recent events in France and similar ones in some other Western countries have convinced me to directly talk to you about them,” Mr. Khamenei writes in the letter. The letter was promoted on Twitter, which is blocked in Iran, under the hashtag #Letter4U.