The EU commisioner for external relations condemned the use of excessive force and urged for dialogue within Iran.
"I think it's a missed opportunity for the Iranian government," Benita Ferrero-Waldner said.
'Meddling with affairs'
As the ministers opened the meeting, Franco Frattini, Italy's foreign minister, said the G8 was working on "a good document that would include condemnation ... but at the same time one that will recognise that electoral procedures are an Iranian question."
The statement is a compromise between countries that wanted to send a tough message to Iran over its suppression of mass street protests and use of violence and others, including Russia, who were careful to keep an avenue open for dialogue over its nuclear programme.
More than 20 people have been killed and many more imprisoned in the protests that followed Iran's election - the worst violence to sweep the country since 1979.
Iranian officials have accused two G8 members, Britain and the US, of inciting the protests and meddling with internal affairs.
Tehran has since said it is considering downgrading ties with Britain after it expelled two diplomats.
The UK followed suit by sending two Iranian diplomats home.
'Exercise in democracy'
The G8 representatives, which also include France, Germany, Italy, Japan, Canada and Russia, started the gathering with a working dinner at the Palazzo della Regione in the city.
Sergei Lavrov, Russia's foreign minister said that Russia was not prepared to sign up to a G8 statement condemning the election itself.
"No one is willing to condemn the election process, because it's an exercise in democracy," he said.
|Frattini said Iran must choose whether it is open to international community or not [AFP]
Lavrov also suggested that overt condemnation would undermine the more important goal of addressing Iran's nuclear programme.
"We must focus on the main objectives that will allow us to move forward to resolve the problem of Iran's nuclear programme," he said.
Frattini said: "Iran is at a turning point.
"It must now choose whether or not it wants to keep the door open to dialogue with the international community - because the open hand from the US, that we supported, must not be greeted with a hand covered in blood."
The meeting, which was initially scheduled to focus on stabilising Afghanistan and moving the Middle East peace process forward, is also meant to lay the groundwork for the G8 summit in two weeks in L'Aquila, the central Italian city devastated by an earthquake in April.
Ministers from Afghanistan and Pakistan will join the G8 ministers later on Friday to discuss a regional approach to Afghanistan's challenges.
The quarter of Middle East peace negotiators - the UN, US, EU and Russia - will also meet on Friday.
The members are expected to back a call by Barack Obama, the US president, for a total freeze on Jewish settlement construction in the occupied West Bank.