Khamenei's response to Obama's letter, which raised the possibility of cooperation between the United States and Iran in fighting against Islamic State militants, was "respectful" but "noncommittal", the Wall Street Journal said, citing an Iranian diplomat.
According to the publication, Khamenei had sent another letter to Obama, outlining abuses that the United States committed against the Iranian people over the last 60 years. The letter was received by Obama in 2009, according to a White House official cited by the Wall Street Journal.
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.
The UN Security Council, the United States, the European Union, and a number of other countries have imposed sanctions on Iran over its nuclear development, which Tehran insists is exclusively for peaceful purposes.
IS is a radical Sunni group that has ceased vast areas in Iraq and Syria. The United States has formed an international coalition, which has been conducting airstrikes against IS targets in Iraq and Syria since September. According to the US State Department, the coalition currently includes 62 countries but Washington has reportedly been looking for more potential members.
