Hekmati on Iranian state TV.

Amir Mirzaei Hekmati's punishment shocked both his family and the Obama administration, who vehemently denied any allegations of Hekmati working with the United States government while in Iran. Hekmati, a former Marine, was expected to be used as a big bargaining chip in the ongoing battle between Iran and the West over Iran's nuclear program.

From the Associated Press:

The United States denied the accusations. The State Department called them a "complete fabrication," and White House spokesman Tommy Vietor added that "allegations that Mr. Hekmati either worked for or was sent to Iran by the CIA are false."

"The Iranian regime has a history of falsely accusing people of being spies, of eliciting forced confessions, and of holding innocent Americans for political reasons," Vietor said in a statement.

The case sheds light on the legal but risky travel of U.S. citizens to Iran, common among many first-generation and second-generation Iranian-Americans but a practice largely hidden to the larger American populace. Thousands are believed to make the trip each year, although the State Department lacks firm figures because people must travel through third countries, and most dual nationals enter the Islamic republic using Iranian passports.

Tehran said earlier this week that it had started to enrich uranium at another site in the country, after several demands from other countries that they shut down their nuclear program. This comes after Iran threatened to close the Strait of Hormuz to shipping earlier this month, which would affect oil trade worldwide.

From the New York Times:

The details of the case against Mr. Hekmati have been cloaked in secrecy since he was detained in August in Iran, where his family says he had traveled to visit his grandparents. Official confirmation that he was even in Iranian custody was not provided until last month. The White House and State Department, noting that Iran prosecutors have a history of coercing confessions, denied Mr. Hekmati was a spy and called for his immediate release. The C.I.A. declined to comment.

Tommy Vietor, a spokesman for the White House’s National Security Council, said “we strongly condemn such a verdict and will work with our partners to convey our condemnation to the Iranian government.”

Iran has a record of arresting and convicting Americans suspected of spying, then freeing them later after bail money has been paid. But rights activists said Mr. Hekmati’s case was the first in the nearly 33-year history of estranged relations with the United States that Iran’s Islamic authorities had ordered the execution of an American citizen.

“This whole case is very politically motivated,” said Hadi Ghaemi, the executive director of the International Campaign for Human Rights in Iran, a a New York-based advocacy group that has been monitoring Mr. Hekmati’s case. “There’s absolutely no evidence against him.”

Swiss diplomats have tried to gain access to Hekmati on behalf of the United States, but Iran has refused access as they do no recognize Hekmati's U.S. citizenship.