The US has warned Iran it will not accept "any outside interference" in Iraq amid concerns that Tehran has sent agents to push its brand of Islamic government.
"We have well-known channels of communication with Iran and we have made clear to Iran that we would oppose any outside interference in Iraq's road to democracy," said White House spokesman Mr Ari Fleischer.
"Infiltration of agents to destabilize the Shi'a population would clearly fall into that category," he told reporters.
Earlier, the New York Times, citing US officials, reported that Iran-trained agents were crossing into southern Iraq to promote friendly Shiite clerics and possibly an Iranian model of Islamic government.
The unnamed officials told the daily that, based on intelligence reports, some agents were members of the Badr Brigade, the military wing of an Iraqi exile group operating from Iran, and irregular members of a special unit of Iran's Revolutionary Guards.
"They are not looking to promote a democratic agenda," one military official told the Times.
Mr Fleischer would not explicitly confirm the report, and dodged repeated questions on how Washington would respond.
"We have concerns about this matter, about Iranian agents in Iraq," he said, adding: "We've made our thoughts clear to the Iranians."
AFP