The visit is Maliki's fourth since he was elected and comes just days after the U.S. handed over military control of the capital's Green Zone to Iraq and began a drawdown that is to lead to all American troops leaving the country by the end of 2011.
Iran's influence in Iraq has grown significantly since the 2003 U.S.-led invasion of Iraq, which toppled the Sunni-dominated government of President Saddam Hussein, a longtime foe of Shiite-run Iran.
Maliki, a Shiite, met Saturday with Iranian Vice President Parviz Davoudi. Today, Maliki is expected to discuss economic, transportation and electricity issues with President Mahmoud Ahmadinejad.
Abdul Hadi Husseini, a parliament member with Maliki's Islamic Dawa Party, said the prime minister's visit was intended, in part, to "make Iran more comfortable and to remove any fear that Iraq could be used as a base" by Western military forces.
"This has been a sticking point for some time between Iran and America and Iran and the rest of world," Husseini said.
Iraq's minister of education, Khudair Khuzai, also an Islamic Dawa member, said Maliki had an additional aim: to help improve relations between the U.S. and Iran.
"We believe that having any tension between those countries will reflect negatively on Iraq," Khuzai said. "Iraq wants to be a [bridge] between both countries."
Iraq's ministers of trade, transportation and electricity accompanied Maliki. Husseini said Iraq was seeking to buy power from Iran and revive supply lines between the two countries.
The visit came as Iraq prepared to close Camp Ashraf, home to a few thousand members of the Iranian militant group Mujahedin Khalq, dedicated to overthrowing Iran's government. The United States had guarded Camp Ashraf, about 40 miles north of Baghdad, since 2003, when the Iranian rebels agreed to disarm in exchange for protection.
Maliki has said that the camp will be closed -- though it is unclear when or how -- and that residents will be allowed to return home or be dispersed to other countries. Maliki said that remaining in Iraq is not an option for members of the group, which is considered a terrorist organization by the U.S.
Also on Saturday, U.S. military officials said troops shot and wounded an Iraqi TV journalist Thursday in the Karada neighborhood of Baghdad. The officials said that the woman was acting suspiciously and that the American soldiers followed "approved defensive measures" after she failed to respond to repeated warnings from them and Iraqi police officers. The soldiers fired two rounds, officials said.
Beladi television identified the woman as Hadeel Emad, a journalist working for the station. She was taken to Yarmouk Hospital, where her left kidney was removed during a four-hour operation.
South of Baghdad, as members of the Qarqouly tribe began to bury at least 23 people killed in a suicide attack at a tribal gathering, Iraqi army officials questioned the father and associates of the 18-year-old tribal member who blew himself up, said U.S. Army Lt. Col. Jim Bradford.
The Iraqi army has discovered weapons caches in the area, including one that probably belonged to the attacker, Bradford said. It contained the same type of munitions used in Friday's bombing, which occurred at a gathering designed to unite Sunni and Shiite members of the clan from across Iraq.
"The village is an honorable village," Bradford said. "They are doing many things well. This was an unfortunate event in the family, in their tribe and in this area. We don't see any indication of continued violence or that this will deter the next step for the government."
Times staff writers Saif Hameed and Ali Hameed and special correspondents in Baghdad contributed to this report.