Ali al-Dabbagh told a news conference in Kuwait on Tuesday: "The situation in Iraq surpasses Iraq's ability to finance development projects."
He was speaking during a meeting of officials from donor nations and the United Nations to discuss Iraqi reconstruction and economic reform.
Iraq's infrastructure was ravaged during the rule of former president Saddam Hussein by decades of sanctions and war , and then by the US-led invasion in 2003 and the violence that followed.
Post-war reconstruction has been hampered by attacks which have forced many projects to be halted and diverted funds away from rebuilding and into increased security.
Iraq's oil industry has been frequently attacked by armed groups opposed to the US presence in Iraq.
Iraqi officials speaking at the meeting said that the country could not re-construct itself until its oil industry was made safe from attack.
"The Iraqi economy is a one-crop economy built on oil only and there are no other revenue sources ... therefore oil exports are being spent on operational expenditure," Dabbagh said.
"Until the oil sector can rise and assume its full role ... we need this sum for the infrastructure and for investment expenditure."
The meeting in Kuwait is the last set of discussions on the International Compact for Iraq, a roadmap for economic reform.
Dabbagh said the agreement also included plans to build dialogue in Iraq between religious and ethnic factions and disband sectarian militias.
"The International Compact represents a carefully-drafted roadmap to clarify how can Iraq, with the help of its international partners, achieve economic self-sufficiency in the medium term," Barham Salih, Iraq's deputy prime minister, said.
To succeed, Iraq needs progress in three areas - "political reconciliation ... achieving security and stability in all regions ... and achieving economic growth and prosperity."
But he said that Iraq will not be able to achieve any of the goals under the compact without generous international support.
Ashraf Qazi, the UN secretary general's special representative to Iraq, told the meeting that in the coming weeks the UN will consult with countries and institutions which had shown interest in helping Iraq.
Iraq hopes to have some of its $40 billion debts to Gulf Arab states paid off or re-scheduled.
Western states have already forgiven Iraq much of its debt but Saudi Arabia and Kuwait, Iraq's biggest Gulf creditors, have made no firm commitments.
Sheikh Mohammad al-Salem al-Sabah, Kuwait's foreign minister, hinted that Kuwait was unlikely to make any decision on the $16 billion that Iraq owes it.
He said that debt forgiveness is a matter for the Kuwaiti parliament to decide on.