The White House expressed "deepest regret and strong objection" on Tuesday to the sentencing of Iranian-American scholar Kian Tajbakhsh, jailed in Iran for his alleged role in post-election unrest.

The White House statement reinforced an earlier call by the State Department for the release of Tajbakhsh, who was among thousands of people detained in the aftermath of the June poll which saw President Mahmoud Ahmadinejad re-elected.

"We express our deepest regret and strong objection that the Islamic Republic of Iran has sentenced Iranian-American scholar Kian Tajbakhsh to 15 years in prison," White House spokesperson Robert Gibbs said in a statement.

"Mr Tajbakhsh poses no threat to Iran or its national security. As an independent and internationally respected scholar, Mr Tajbakhsh has dedicated his life to fostering greater understanding between Iran and the international community.

"He embodies what is possible between our two countries. Our thoughts and prayers are with Kian's family and loved ones on this difficult day," Gibbs said.

"We urge Iran to release Mr Tajbakhsh as soon as possible."

Earlier the State Department urged Tehran "to quickly resolve all outstanding cases involving American citizens, including Joshua Fattal, Shane Bauer, Sarah Shourd, Reza Taghavi and Robert Levinson."

The five were arrested Iranian security officials when hiking on the Iran-Iraq border in July.

Amid tensions over Iran's nuclear programme and detainees, fifty US lawmakers urged Obama to slap sanctions on foreign firms with investments of more than $20-million in Iran's energy sector as called for under US law.

AFP

ET back on his high horse "We are being oppressed again. We will rise again." Eugene Terre'Blanche is back. Again.

Time to say goodbye? Mmm... Mmmaa... Mmmaaleh... The Point would like to boycott the chubby-cheeked one.

Visit our politics page Need the latest political news, features, interviews and profiles? Visit our dedicated page...