"The claim made by Wall Street Journal is an unprofessional media game," the Iranian Foreign Ministry Spokeswoman Marziyeh Afkham said on Sunday, according to IRNA news agency. She said that Obama has sent letters to Iran in the past and that "in some cases Iran responded to his letters," but that "there is no new letter."
On February 14, the Wall Street Journal published a very detailed article about a purported reply from Ayatollah Khamenei. In the article, the publication cited an unnamed Iranian diplomat, who explained the details of the purported letter, which claimed that Iran was "respectful" but "noncommittal" to the possibility of Iran joining the US in combating ISIL. The White House has not commented on the legitimacy of the purported letter.
The United States has been part of the ongoing talks between Iran and the P5+1 group on the controversial Iranian nuclear program, which the West suspects to be a cover-up for the development of nuclear weapons.