East Of Baquba, Iraq: The US military commander in Iraq stepped up accusations over the weekend that Iran was stoking violence in Iraq and said Tehran's ambassador to Baghdad was a member of the Revolutionary Guards Qods force.

Washington accuses the elite unit of Iran's Revolutionary Guards of inciting bloodshed in Iraq and of training and equipping militias who have attacked US troops.

General David Petraeus, speaking at a US military base about 30 km from the Iranian border on Saturday, said Iran was giving advanced weaponry to militias in Iraq.

"They are responsible for providing the weapons, the training, the funding and in some cases the direction for operations that have indeed killed US soldiers," Petraeus told a small group of reporters when asked if the Iranian government was responsible for killing US troops.

"There is no question about the connection between Iran and these components, (the) attacks that have killed our soldiers."

Petraeus did not say how he knew Iran's ambassador to Baghdad, Hassan Kazemi-Qomi, was a member of the Qods force.

"The ambassador is a Qods force member," said Petraeus, before appearing to suggest that Kazemi-Qomi was not under the US military spotlight because he was a diplomat.

"Now he has diplomatic immunity and therefore he is obviously not subject (to scrutiny). He is acting as a diplomat."

The Iranian embassy in Baghdad had no immediate comment.

Kazemi-Qomi has twice met US ambassador Ryan Crocker in Baghdad this year for landmark talks on ways to stabilise Iraq. The discussions have made little headway, with both sides accusing each other over the violence in the country.