Washington: Secretary of State Hillary Rodham Clinton on Wednesday ruled out Iranian President Mahmoud Ahmadinejad's suggestion that three detained American hikers in Iran be swapped with Iranian citizens held in the United States.

Clinton said that the hikers, along with other Americans jailed in Iran, should be released immediately on humanitarian grounds. She said there is no basis for their continued detention.

"We call on Iran to release all of the American citizens that they have currently detained," she told reporters.

"We believe they are being unjustly detained and they should be released without further delay. We also are very committed to making it clear to the Iranians that they should do so on humanitarian grounds since the detention of our citizens is baseless."

Her comments came a day after Ahmadinejad suggested in a television interview that the three American hikers be traded for Iranians that Tehran says are currently in US jails. Ahmadinejad also suggested that there were talks under way regarding such a swap, something Clinton denied.

"There are no negotiations going on between us and the Iranians," she said. "They should unilaterally release our detained citizens.

Clinton said the Iranian government is fully aware that if it has questions about Iranians in US jails, it can request information through proper channels.

Iranian authorities arrested the three hikers - Shane Bauer, Sarah Shourd and Josh Fattal - in late July after they strayed across the Iranian border from Iraq's northern Kurdistan region where they were hiking. Their families have said they accidentally crossed the border and meant no harm.

In addition to the hikers, the State Department says it is aware of at least two other Americans detained in Iran.