Iran's Supreme Leader Ayatollah Ali Khamenei has sent a secret letter to US President Barack Obama. According to an Iranian diplomat, the cleric sent the letter in response to a presidential letter from Obama last October, in which the American president suggested the possibility of U.S.-Iranian cooperation in fighting Islamic State if a nuclear deal was secured.
The Iranian diplomat added that Khamenei's letter was "respectful" but noncommittal. However, both the White House and the Iranian mission in the US refused to comment. But a US National Security Council spokesperson said the focus remained exclusively on Iran's nuclear program.
Six world powers want Iran to curb its nuclear programme in return for lifting sanctions. The deadline for an accord has been extended to the end of June this year, after talks in Vienna failed.