( CNN ) -- U.S. President Obama sent a direct message to Iran 's Supreme Leader Ayatollah Ali Khamenei weeks before this month 's disputed election , Iranian sources said Wednesday . Iran 's supreme leader , Ayatollah Ali Khamenei , calls for an end to protests last week at Tehran University . The letter requested dialogue and engagement between the two nations , the sources said . The sources said that Khamenei has yet to reply to the letter but that nonetheless it `` had set the negotiating table in order for both sides to sit around it after the election . '' The White House refused to `` get into the specifics of our different ways of communicating , '' a senior Obama administration official said . `` We have indicated a willingness to talk for a long time and have sought to communicate with the Iranians in a variety of ways , '' the official said . Khamenei made an indirect reference to the letter in his sermon on Friday at Tehran University . `` The U.S. president said that we were waiting for a day like this to see people on the street , '' the Iranian leader said . `` Some people attributed these remarks to Obama , and then they write letters to say we 're ready to have ties , that we respect the Islamic Republic , and on the other hand , they make such comments . Which one should we believe ? '' One Iranian source said , `` We thought President Obama would send congratulations to President Ahmadinejad , '' and before the election , his senior advisers prepared a response to the anticipated note , which never came . The Iranian source said the election dispute is wasting time on the issue of starting U.S.-Iranian negotiations . Watch how the reported letter is part of a new policy of engagement » . `` The longer it is delayed , '' the source said , `` the less likely [ U.S.-Iranian talks ] will happen . '' Another Iranian government official said there is still `` no trust '' between Iran and the United States . The source said he is waiting for `` real change '' even though the Iranian government welcomed the change in tone of the Obama administration before the current election turmoil in Iran . The official went on to cite a recent gesture by Iran toward Obama : the release of journalist Roxana Saberi . The official said Iran accepted Obama 's assurances that she was not a spy and had allowed the Iranian citizen to leave the country . Since , under intense scrutiny amid growing concerns over Tehran 's violent crackdown on street protests , Obama has sharpened his language on Iran . `` The United States and the international community have been appalled and outraged by the threats , beatings and imprisonments of the last few days , '' Obama said Tuesday , adding that he strongly condemns `` these unjust actions . '' He has not spoken in support of Ahmadinejad or his main rival , Mir Hossein Moussavi , whose supporters have taken to the streets to protest the results of the June 12 election that gave Ahmadinejad a second term . Obama 's letter to Khamenei is in keeping with his publicly stated aim of engagement with Iran and his New Year 's message in which he described a new way forward . The Obama administration has `` made it clear that any real dialogue -- multilateral or bilateral -- needed to be authoritative , '' according to the senior administration official . The official noted that the Iranians have yet to respond to a diplomatic outreach made during talks on Iran 's nuclear program April 8 . At that time , the administration asked the European Union 's international policy chief , Javier Solana , to invite Iran to new talks with the permanent members of the U.N. Security Council and Germany . But the administration 's tack toward Iran may be changing , as senior officials in Washington said the Obama administration is seriously considering not extending further invitations to Iranian diplomats for July 4 celebrations overseas . Some invitations had been sent and will not be rescinded , senior administration officials said . The officials said intense discussions on the issue were taking place , but the final decision had not been made . The Obama administration had decided to invite Iranians to the celebrations at overseas posts as part of Obama 's policy of engaging the Iranian regime . As part of that engagement , Obama videotaped a message for the Iranian people on the Persian new year , and U.S. officials have engaged members of the Iranian government . CNN 's Elise Labott and Dan Lothian contributed to this report .
Obama refuses to `` get into the specifics , '' administration official says . White House 's letter requested dialogue and engagement , Iranians sources say . Sources : Ayatollah Ali Khamenei has n't replied to letter sent before sermon last week election . Ayatollah Ali Khamenei made an indirect reference to letter in sermon last week .