President Massum made the remarks in a meeting with Iranian First Vice President Fuad Massum in Baghdad on Thursday.
The Iraqi president expressed Baghdad's willingness to expand ties with allies and neighboring countries, and said that he was looking forward to using Iran's experience in dealing with various issues, ranging from banking to environment.
"Baghdad welcomes Iranian investment in Iraq's economic projects and wants Iran's private sector to take on a more serious role in this regard," he noted.
Jahangiri, for his part, reassured President Massum that his country will help reconstruct Iraq just as it helped it defeat the ISIL Takfiri group because of the deep bonds between the two neighboring countries.
"In the fight against the ISIL, we showed that Iran was inseparable from Iraq and now that Iraq's reconstruction is on the agenda, we are ready to assist the Iraqi government and nation because we view Iraq's security and prosperity as Iran's own security and prosperity," Jahangiri said.
The Iranian vice president, meantime, said ties between Iran and Iraq had reached the highest possible level and could serve as an example for the region.
He pointed to Iraq's vital role in the Muslim world and the international community, and said it was fine Islamic and political leadership as well as a progressive constitution that helped Iraq prevail.
Jahangiri also called on all of Iraq's ethnic, religious and political factions to remain united through the constitution because unity was their only key to victory.
"This is the most important factor for Iraq's advancement and the eradication of terror," he added.
The Iranian first vice president said Tehran and Baghdad needed to further increase their economic ties as well and break the $7 billion dollar barrier in mutual trade.
Jahangiri, who is on a visit to Iraq, also met with Iraqi Parliament Speaker Salim al-Jabouri and Iraqi Islamic Party Secretary General Ayad al-Samarrai.