Tehran (AFP) - Iran's FM Javad Zarif called the detention of one of its journalists in the United States a "political action" that tramples on freedom of speech and demanded her immediate release.
"The arrest of Marzieh Hashemi by America is an unacceptable political act that tramples on freedom of speech," Zarif told state run Al-Alam TV on Wednesday.
US-born Hashemi, who works for Iran's English-language Press TV, was arrested on arrival at St Louis Lambert International Airport on Sunday, according to family and friends cited by Press TV.
Zarif said that since Hashemi was married to an Iranian she is considered as an Iranian national and "it is our duty to defend our citizens."
"The Americans must immediately end this political game," he added, demanding her release.
Earlier on Wednesday the head of Press TV said that Hashemi had been detained with her son in the United States on unspecified charges.
"As we know the US, especially on combatting terrorism, can arrest anyone with no charges and detain them for weeks. We believe legal action would not be effective for her freedom," Payman Jabali told reporters in Tehran.
"We call on the US to explain her charges," he said. "This is a scandal for so-called US democracy."
Jabali said she may have been targeted over documentaries she made about US activities in the Middle East, Islamophobia and other issues.
The broadcaster said Hashemi, a Muslim convert who changed her name from Melanie Franklin, had been visiting "her ill brother and other family members".
Jabali said all she had been offered to eat was pork, religiously forbidden for Muslims.
He said her son, Reza Hashemi, had also been arrested but was not in detention while he awaited trial.