WASHINGTON - The US State Department on Monday urged Iran to either hand over or prosecute a suspect in the alleged assassination plot on the Saudi ambassador in America.

"According to the International Convention on Protected Persons, Iran's government has a choice either to extradite this person, this individual, or submit the case for prosecution on its own," State Department spokesman Mark Toner told reporters in a regular briefing.

The comment came after the United States said last Tuesday that Manssor Arbabsayara, a 56-year-old US citizen holding both Iranian and US passports, and Gholam Shakuri, a member of Iran's Islamic Revolutionary Guard Corps, were charged with sponsoring and promoting terrorist activities abroad, including a plot to assassinate the Saudi ambassador to the United States. Arbabsayara was arrested by the US authorities, while Shakuri remains in Iran.

The high-profile accusations have brought fresh tensions to relations between the two arch-foes, with Iran fiercely denying such charges. Iran's Foreign Minister Ali-Akbar Salehi also said Monday that the Islamic Republic is ready to examine evidences related to the case.

Toner said consular access does not "apply necessarily to dual- national citizens," referring to Arbabsayara who holds both Iranian and US passports.

"That said, when an individual possessing US citizenship and that of another country is arrested or detained in the US, the State Department has long urged responsible authorities to permit consular visits by consular officers of the other country or nationality, in this case Iran," he said.

"So we would obviously lobby for that or talk to local authorities to encourage them to allow those visits," said Toner.