The secretary of Iran’s Supreme National Security Council, Ali Shamkhani, acknowledged not only that US President Barack Obama had written letters to Iran’s supreme leader, but also that there have responses to some of them.

“The letters of the American president have a history of some years, and in some instances, there have been responses to these letters,” said Shamkhani Nov. 12 at a weekly meeting of national security officials.

Shamkhani, who served as defense minister from 1997 to 2005 and is now Supreme Leader Ayatollah Ali Khamenei’s representative to the council, did not elaborate on which of Obama’s letters received a response, in what form or from which official. From summer 2009 to October 2014, four letters were reported to pass from Obama to Ayatollah Khamenei.

However, according to the transcript provided by Iranian Students’ News Agency, Shamkhani said that there are “contradictions” between the contents of these secret letters and US public positions. In contrast to the United States, Shamkhani said that Iran’s private and public positions have been the same, particularly when it comes to the nuclear program.