TEHRAN, Iran (AP) - Iran's Supreme Leader warned Sunday against undermining negotiators engaged in talks with the West, a message directed apparently at hard-liners who have criticized Iran's diplomacy over its nuclear program.
    
The remarks by Ayatollah Ali Khamenei were his latest show of support for President Hassan Rouhani's policy of outreach to the West. They come ahead of a new round of talks scheduled for Thursday in Geneva.
    
Diplomats "are on a difficult mission and nobody should weaken those who are on assignment," the official IRNA news agency quoted Khamenei, who has final say on all matters of state, as telling a group of students.
    
"Nobody should consider our negotiators as compromise-seekers," Khamenei said. Iranian officials maintain that the country will not concede what it considers to be its fundamental right to nuclear activity.
    
Hard-liners have accused diplomats of being overly optimistic and keeping details of the talk's secret.
    
Khamenei said the nuclear talks with world powers, five permanent members of the UN Security Council plus Germany, will be limited to the nuclear issue. Hard-liners have also criticized Rouhani for pursuing broader rapprochement, and took particular exception to a short September phone call between him and President Barack Obama aimed at ending over three decades of estrangement between the countries.
    
Khamenei criticized Washington for repeating its threats against Iran's nuclear facilities.
    
"On one hand, the Americans smile and show interest in talks but on the other hand they immediately say all options are on the table," Khamenei was quoted as saying by state TV.
    
Both the U.S. and Israel have not ruled out a military option against Iran's nuclear facilities.
    
The West suspects Iran is developing weapons technology. Iran denies it, saying its nuclear program is for peaceful purposes like power generation and cancer treatment.
    
Khamenei reiterated his previous position that he is not optimistic about nuclear talks, but added that they will not damage Iran.
    
Khamenei also praised Iranian militant students who stormed the U.S. embassy in 1979, sparking a crisis that contributed significantly to the bitterness between the two countries.
    
"Thirty years ago, our young people called the U.S. Embassy a 'den of spies'... It means our young people were 30 years ahead of their time," he said, a reference to a series of reports of U.S. eavesdropping on foreign leaders, including German Chancellor Angela Merkel.
    
Hard-line factions have pledged to stage a major anti-U.S. rally Nov. 4, the anniversary of the takeover. The date is marked each year by gatherings outside the former embassy's brick walls, which are covered with anti-American murals. But the fervor has waned in recent years, with authorities bringing school children by bus to help fill out the crowds. It is seen as an opportunity for hard-liners to put further pressure on Rouhani's diplomacy.