Iran and Iraq agreed to boost defense cooperation during a visit of Iraqi Prime Minister Nuri al-Maliki to Tehran on Monday, Iran's official IRNA news agency said, giving few details on the content of the agreement.
Iran's Defense Minister Mostafa Mohammad Najjar signed a memorandum of understanding on defense cooperation with his Iraqi counterpart, Abdul Qader Jassim, IRNA said.
Mine clearance and the search for soldiers missing in action would be part of the planned cooperation, it said.
The two majority Shiite Muslim countries fought an eight-year war in the 1980s, in which 1 million people were killed, but ties have improved since Sunni Arab strongman Saddam Hussein was ousted in the US-led invasion of Iraq in 2003.
"The two parties, stressing the importance of defense cooperation in the balanced expansion of ties ... called for development of this sort of cooperation with the aim of strengthening peace and stability in the region," IRNA said.
Earlier on Monday, Iran's supreme leader told Maliki that the presence of US forces in Iraq was the biggest obstacle to its development as a united country.
Ayatollah Ali Khamenei hit out at the "occupiers" in Iraq at a time when Baghdad is negotiating with the United States on a new agreement aimed at giving a legal basis for US troops to stay in Iraq after December 31, 2008, when their UN mandate expires.
Iran blames the presence of US troops for the violence that followed the US-led invasion of Iraq five years ago.
The United States accuses Iran of arming, training and funding Shiite militias in Iraq. Tehran denies the charge.