Iraqi President Jalal Talabani has arrived in Teheran for discussions on bilateral relations, Iran's official news agency said.
The late Thursday report by IRNA said Talabani would meet Iranian President Mahmoud Ahmadinejad and other leaders during his three-day visit.
Talabani last visited Iran in 2007.
The neighboring countries have had close relations after the 2003 overthrow of Iraqi dictator Saddam Hussein, who fought an eight-year war against Iran in the 1980s. The war left some one million casualties on both sides.
The United States has repeatedly accused overwhelmingly-Shi'ite Iran of using its influence in the majority-Shi'ite Iraq to fight US-led forces.
Iran has denied the charge, saying the US occupation has caused security concerns there.