WASHINGTON (CNN) -- Iraq's Interior Ministry is regarded as "dysfunctional and sectarian," and the National Police should be "disbanded and reorganized," according to an independent report obtained by CNN.

Iraqi armed forces patrol the streets of Karbala during a celebration August 27.

The report, produced by the Independent Commission on Security Forces in Iraq, fires stinging criticism at Iraqi security forces but also includes promising words for the country's military.

Ordered by Congress, the report comes less than a week before the White House is expected to provide to lawmakers a highly anticipated assessment of President Bush's addition this year of some 30,000 troops to Iraq. Part of the reason for the increase was to reduce sectarian killings that have spread throughout much of Iraq since 2006.

The independent report, set for release Thursday, says Iraq's Interior Ministry "is a ministry in name only." It "suffers from ineffective leadership" and "is widely regarded as dysfunctional and sectarian," the report says. Watch the top House Democrat say the report is evidence of a failed Iraq policy »

The Interior Ministry and the National Police force it operates have long been regarded by observers as being infiltrated by sectarian Shiite militias.

"Such fundamental flaws present a serious obstacle to achieving the levels of readiness, capability, and effectiveness in police and border security forces that are essential for internal security and stability in Iraq," the report says.

"Sectarianism in its units undermines its ability to provide security; the force is not viable in its current form. The National Police should be disbanded and reorganized," it says.

The Pentagon said Wednesday it does not agree with the report's recommendation that the Iraqi National Police be disbanded.

The commission, headed by Gen. James L. Jones, the former top commander in Europe, said Iraq's armed forces won't be ready to perform independently during the next 18 months. The Bush administration has often cited the ability of Iraq's newly created military to stand on its own as a requisite for U.S. troop withdrawals.

"We've always recognized that this is a long-term project," said Pentagon spokesman Geoff Morrell, who had not seen the report. "Getting the Iraqi army on its feet and capable of defending the borders of that country independently is not an overnight project, and we are continuing to work on it."

The Pentagon is committed to rebuilding the Iraqi army, Morrell said.

"I don't know if it takes 12 months, I don't know if it takes six months, I don't know if it takes longer," Morrell said. "But we are committed to stay as long as it takes to help the Iraqi army gets back on its feet to the point that they're able to take on the normal functions of an army."

Morrell said the size of Iraq's police should be put into context. "The National Police are 25,000 police officers," he said. "It's not reflective of the entire Ministry of Interior police force, which I think includes roughly 300,000 local and provincial police as well."

The report says the Iraqi Police Service "is incapable today of providing security at a level sufficient to protect Iraqi neighborhoods from insurgents and sectarian violence."

The report says the "Iraqi Police Service must be better trained and equipped," and the commission "believes that the Iraqi Police Service can improve rapidly should the Ministry of Interior become a more functional institution."

The report has promising words for the Iraqi army, special forces, navy and air force, describing them as "increasingly effective" and "capable of assuming greater responsibility for the internal security of Iraq."

"The commission assesses that in the next 12 to 18 months, there will be continued improvement in their readiness and capability, but not the ability to operate independently. Evidence indicates that the ISF [Iraqi Security Forces] will not be able to progress enough in the near term to secure Iraqi borders against conventional military and external threats."

In addition, Iraq's Department of Border Enforcement "suffers from poor ministerial support from the MOI [Ministry of Interior]," the report says.

"Border forces often lack the equipment, infrastructure and basic supplies to conduct their mission. Overall border security is further undermined by the division of responsibilities between the MOI and the Ministry of Transportation. Corruption and external influence and infiltration are widespread. Absent major improvements in all these areas, Iraq's borders will remain porous and poorly defended."

Other key conclusions of the report include:

The Defense Ministry "is building the necessary institutions and processes to fulfill its mission. However, its capacity is hampered by bureaucratic inexperience, excessive layering, and overcentralization. These flaws reduce the operational readiness, capability, and effectiveness of the Iraqi military."

The Iraqi army and special forces "possess an adequate supply of willing and able manpower and a steadily improving basic training capability" and "are making efforts to reduce sectarian influence within their ranks and are achieving some progress. Substantial progress can be achieved to that end."

The "Iraqi air force's relatively late establishment hampers its ability to provide much-needed air support to ground operations" but "it is nonetheless progressing at a promising rate during this formative period."

"The Iraqi navy is small and its current fleet is insufficient to execute its mission. However, it is making substantive progress in this early stage of development."

CNN's Jessica Yellin contributed to this report.

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