Iran's supreme leader has given new support to President Hassan Rouhani's negotiations with Western nations over the country's nuclear program.
Iranian news services say Ayatollah Ali Khamenei expressed his feelings about the negotiations Sunday during a speech before a group of students. Iranian diplomats will hold another round of talks later this week in Geneva with negotiators from the five permanent members of the United Nations Security Council -- the United States, France, Britain, Russia and China -- plus Germany.
Khamenei said no one should consider the negotiators as "compromisers," and warned that "nobody should weaken" them during what he called a "difficult mission."
Khamenei said he remains pessimistic about the chances for an agreement, but said Iran would not be harmed if they failed.
The supreme leader also denounced Washington's stance toward Iran, describing the U.S. as "a smiling enemy" who has called for negotiations while still threatening military action.
Khamenei's speech occurred on the eve of the anniversary of the 1979 seizure of the U.S. Embassy in Tehran.
The United States and its Western allies suspect Iran is developing nuclear weapons. Iran has denied the charge, saying its nuclear program is designed for peaceful purposes.