In a statement late on Sunday, Iran's Foreign Ministry Spokeswoman Marziyeh Afkham described the report by the American newspaper as “an unprofessional media ploy."
"There is no new letter," she underlined.
She, at the same time, emphasized that the US president has previously sent a number of letters to Iran, which have been answered in some cases.
Wall Street Journal on February 13 quoted an unnamed Iranian diplomat as saying that the Supreme Leader has sent a letter to Obama in recent weeks in response to an October presidential letter that raised the possibility of Iran-US cooperation in fighting against the Islamic State in Iraq and the Levant (ISIL) terrorist group if a nuclear deal is secured.
According to the report, a senior White House official declined to confirm the existence of that letter.