"We hear mixed responses all the time from the government. They're going to let her out, they're going to let her out in two months, they're going to sentence her to eight years, they're going to do an appeal," Clinton told a Senate panel.
"I think it shows how difficult it is to deal with this government in Iran," she said.
Saberi was "extremely unhapppy and is on a hunger strike," said Clinton.
The top US diplomat reiterated that Washington had grave concerns about Saberi's health and that it was pursuing "every channel" to secure her release.
The journalist's father, Reza Saberi, told AFP in Tehran that his daughter was now into her second week on a hunger strike, in which she takes only sugared water. He said she had lost a lot of weight, but would keep up her protest until she is released.
Saberi, who marked her 32nd birthday in jail Sunday, was sentenced to eight years in prison on charges of spying for the United States, allegations Washington says are unfounded.
Saberi has both US and Iranian citizenship, but Tehran does not recognize dual nationality.
Saberi, who is also partly of Japanese descent, has reported for the US National Public Radio, the BBC and Fox News and has lived in Iran for the past six years.
In a rare move, President Mahmoud Ahmadinejad has appealed for a fair trial.
Her detention has come amid a bid by President Barack Obama to open up diplomatic contacts with Iran, an arch US foe since its 1979 Islamic Revolution.
