Sakineh Mohammadi Ashtiani's son has told an Italian news agency he was appealing to Pope Benedict XVI and to Italy to try to stop his mother's execution. (Amnesty International/Associated Press)

Iran's suspension of a stoning sentence against a woman convicted of adultery is not enough: it must be completely overturned, the European Union presidency said Thursday.

Foreign Minister Steven Vanackere of Belgium, which holds the EU's rotating presidency, said that Iran's concession that the punishment against Sakineh Mohammadi Ashtiani could be eased did not meet the human rights conditions the EU is insisting on.

He said the Belgian presidency would work hard "to achieve that the punishment will be unequivocally repealed." This week, several European Union nations and the continent's biggest human rights organization have criticized Iran for its plan to stone the 43-year-old mother of two even if Tehran has put the plan on hold for now.

The plight of Ashtiani has caused a global outcry and widespread criticism of Iran's justice system, which still includes stoning.

"This inhuman conviction is indefensible and has raised our abhorrence," Vanackere said in a statement. "Human rights, particularly women's rights, are systematically thwarted" in Iran.

Iran says it has put the stoning on hold for now, but has also indicated Ashtiani could be hanged for her conviction of playing a role in her husband's 2005 murder.

Late Wednesday, Tehran's envoy to the Holy See held out hope for some easing of punishment.

Ambassador Ali Akbar Naseri stressed though that Ashtiani had "had illicit relations with numerous men" and had been involved in the killing of her husband. "Her guilt has been demonstrated," he said.

Earlier this week, European Commission President Jose Manuel Barroso called stoning "barbaric" and several EU nations also criticized Tehran for its stand. They were joined by the European Parliament and the 47-nation Council of Europe human rights organization.

Ashtiani's lawyer, Houtan Javid Kian, has said that there has been no change in her case and the stoning sentence was suspended but not officially cancelled. He has said Ashtiani was never formally put on trial on the charge of being an accomplice to murder and was not allowed to mount a defence.