Iran's defence minister has visited a joint intelligence centre in the Iraqi capital operated by Iran, Iraq, Syria and Russia.
Brigade General Amir Hatami met with Iraq's interior minister and other officials, and praised their victory over the Islamic State group, Iran's official news agency IRNA said.
Gen. Saad al-Alak, head of Iraq's military intelligence, who met with Hatami, called the four-nation alliance "a distinguished example for international relations, especially in the field of military and security cooperation."
Iran has maintained close ties to the Iraqi government since the 2003 US-led invasion. It sponsors a number of state-sanctioned militias, which helped Iraqi forces in the fight against Islamic State group.
Iran, along with Russia, is a close ally of Syrian President Bashar Assad, responsible for violently suppressing a peaceful uprising in 2011, leading the country to war.
Tensions between Iran and rival Saudi Arabia are rising, causing shockwaves of proxy conflicts across the region.
Saudi Arabia's King Salman opened the 29th annual Arab League summit on Sunday by criticising Iran's "blatant interference" in regional affairs.
Arab leaders met in Saudi Arabia as world powers face off over Syria amid rising tensions between Riyadh and Tehran.
In his opening speech, Salman notably made no mention of the Western strikes launched against the Assad regime a day before.
Saudi Arabia pushed instead for a tough, unified stance against its regional arch-foe Iran.
"We renew our strong condemnation of Iran's terrorist acts in the Arab region and reject its blatant interference in the affairs of Arab countries," the king said.