Iran's vice-president has said efforts to improve security in Iraq depend on the withdrawal of US-led forces and an end to US interference in the country.
Mr Davoodi (r) said Iraq's security was Iran's security
Parviz Davoodi said Iran wanted a secure and stable Iraq, and was doing what it could to achieve this.
He was speaking after a second day of talks in Tehran between senior Iranian officials and Iraqi PM Nouri Maliki.
US commanders have repeatedly accused Iran of training and arming sectarian militias in Iraq, which Tehran denies.
The BBC's Pam O'Toole in Tehran says the two countries have forged increasingly close ties and Mr Maliki received a warm welcome there.
On Wednesday evening, Mr Maliki met Iranian President Mahmoud Ahmadinejad.
Iranian media said that after the meeting Mr Maliki expressed appreciation for Iran's positive and constructive stance on Iraq, including providing security and fighting against what he described as terrorism.
Several Iranian officials criticised the US position in Iraq.
"Establishment of peace and tranquility in Iraq depends on withdrawal of occupiers and their avoidance from interfering in Iraq, and also on the authority of the government of Mr Maliki," Mr Davoodi said after talks with the prime minister.
"We regard Iraq's security as our own security and that of the region," he added.
Iraqi officials have said Mr Maliki will be seeking further co-operation from Iran in helping to quell the violence in his country.