The United States said Tuesday that Swiss diplomats serving US interests in Tehran have confirmed the death sentence handed to US-Iranian ex-Marine Amir Mirzai Hekmati.
The United States said Monday that it had only seen Iranian press reports that Hekmati had been condemned to death for membership in the CIA and involvement in terrorism, accusations Washington strenuously denies.
"The Swiss protecting power has now been able to confirm to us the verdict," State Department spokeswoman Victoria Nuland told reporters.
"So we strongly condemn the death sentence verdict given to Mr. Hekmati. We've conveyed our condemnation to the Iranian government through the Swiss protecting power," Nuland said.
Switzerland represents US interests in Tehran in the absence of diplomatic relations between the two countries following the 1979 Islamic revolution that overthrew the US-backed Shah of Iran.
"We maintain, as we have from the beginning, that these charges against him are a fabrication. We call on the Iranian authorities to release him immediately," she said.
"We've also called on them to allow him to have legal counsel; defendants in Iran are allowed to appeal within 20 days," Nuland said.
She said the United States also urged Iran to respect "the fact that he is a US citizen and grant the Swiss protecting power access to him."
The United States said Swiss diplomats have tried several times to see Hekmati but have been refused.
Hekmati, a 28-year-old former US Marine born in the United States to an Iranian family, was "sentenced to death for cooperating with a hostile nation, membership of the CIA and trying to implicate Iran in terrorism," a judge in Tehran ruled, according to reports by the Fars and ISNA news agencies.
The ruling further ratcheted up a war of words between Iran and the United States as tensions flare over Tehran's nuclear program and an Iranian threat to close the crucial Gulf of Hormuz oil transit route.
The accused was shown on state television in mid-December saying in fluent Farsi and English that he was a Central Intelligence Agency operative sent to infiltrate Iran's intelligence ministry.
Iranian officials said his cover was blown by agents for Iran who spotted him at the US-run Bagram military air base in Afghanistan.
Hekmati's family in the United States told US media he had traveled to Iran to visit his grandmothers and insisted he was not a spy.
In his sole trial hearing, on December 27, prosecutors relied on Hekmati's "confession" to say he tried to penetrate the intelligence ministry by posing as a disaffected former US soldier with classified information to give.