Iraqi critics of the agreement said that it means Iraq will be a client state in which the United States will keep more than 50 military bases and American soldiers will enjoy legal immunity.

Iranian President Mahmoud Ahmadinejad(R) meets with visiting Iraqi Prime Minister Nuri al-Maliki(L) in Tehran on Sunday, June 8, 2008.(Xinhua/AFP Photo) 

Iran fiercely opposes the agreement, which is expected to be signed by midsummer, and has always called for the immediate withdrawal of US troops from Iraq.

On early Sunday, after his late-night talks with Iranian Foreign Minister Manouchehr Mottaki in Tehran, al-Maliki said that Iraq would not become a platform to "harm" neighboring Iran, the official IRNA news agency reported.

The Baghdad government "will not allow Iraq to become a platform for harming the security of Iran and other neighbors," al-Maliki was quoted as saying.