Iranian insults against Bruni 'unacceptable' - France
France has said "insults" in the Iranian media aimed at its first lady, Carla Bruni-Sarkozy, are unacceptable.
One state-run newspaper denounced her as a prostitute after she publicly criticised Iran for threatening to stone an Iranian woman to death.
Iran urged its media not to insult foreign dignitaries.
But Kayhan, the paper which made the original comments, went on to call for Mrs Bruni-Sarkozy's death.
In a statement, the French foreign ministry said: "We are letting the Iranian authorities know that the insults put out by the daily newspaper Kayhan and taken up by Iranian websites regarding several French personalities, including Mrs Carla Bruni-Sarkozy, were unacceptable."
Ashtiani faces the death sentence after being convicted by an Iranian court of infidelity towards her husband and complicity in his murder.
On Tuesday, Kayhan, which acts as a mouthpiece for Iran's conservative Islamic leadership, reiterated its attack, adding that the Italian-born French first lady deserved to die for supporting her.
"This Italian prostitute's indignation at Kayhan's report came while she has had illegitimate relationships with different people before and after marrying [French President Nicolas] Sarkozy," Kayhan said.
"Reviewing Carla Bruni's records clearly shows why this immoral woman has supported an Iranian woman who has committed adultery, has contributed to the murdering of her husband and has been sentenced to death, and in fact she herself [Mrs Bruni-Sarkozy] deserves death."
Earlier, a spokesman for the Iranian foreign ministry, Ramin Mehmanparast, urged the country's media not to insult foreign dignitaries.
"Insulting the officials of other countries and using inappropriate words, this is not approved of by the Islamic Republic of Iran," he said.
"The policies, the manners and the comments of other countries' officials, we criticise them, we make objections to them and we call for reviewing their deeds - but we don't think using inappropriate words and insulting words is the right thing to do."
Mrs Bruni-Sarkozy is part of an international campaign to save the life of the 43-year-old Iranian mother-of-two.
In an open letter to her, she wrote: "Why shed your blood and deprive your children of their mother?
"Because you have lived, because you have loved, because you're a woman, and because you're an Iranian? Everything within me refuses to accept it".
The responding editorial in Kayhan on Monday, titled "French prostitutes join the human rights protest", accused the French first lady of being a hypocrite, referring to her previous relationships with high-profile celebrities.
France has urged the European Union to threaten new sanctions over the case.