Khamenei’s speech pulled the rug out from underneath the administration.
Check it out:

President Obama has long known that the real decision maker in Iran is Ayatollah Khamenei, the so-called supreme leader. While other Iranian officials have negotiated with Western powers over the mullahs’ nuclear program, Khamenei’s opinion is the only one that really counts. It is for this reason that Obama began writing directly to Khamenei early in his presidency.