Billions of dollars worth of U.S.-funded reconstruction projects in Afghanistan and Iraq could fall into disrepair over the next few years because inadequate provisions have been made to pay for their ongoing operations and maintenance, according to a report to be released Friday by a bipartisan legislative commission.

The Commission on Wartime Contracting in Iraq and Afghanistan says it “sees no indication” that the Pentagon, the State Department and the U.S. Agency for International Development are “effectively taking sustainability risks into account when devising new projects or programs.”

If immediate steps are not taken to address sustainability issues, the commission says, “the United States faces new waves of waste in Iraq and Afghanistan.”

One of the commission’s chairmen, Christopher Shays, a former Republican congressman from Connecticut, said in an interview that the cost of projects that cannot — or will not — be sustained by the Iraqi and Afghan governments “will make other forms of [contracting] waste pale in comparison.”

In a report issued in February, the commission estimated that those other forms of waste, including fraud and abuse, amounted to tens of billions of dollars of the $177 billion obligated by Congress since 2001 to support U.S. operations in Iraq and Afghanistan.

Military officials involved in Iraq and Afghan reconstruction have acknowledged problems with sustaining some projects, but they insist that many of their initiatives will provide benefits long after U.S. forces depart. USAID spokesman Lars Anderson said the agency “fully recognizes the importance of ensuring that the Afghan government and people have the interest, capacity and a plan to resource all the work that we are undertaking together, including putting systems in place to increase domestic revenues to support these efforts.”

High on the contracting commission’s list of concerns is the U.S. effort to build a new Afghan army and police force, which will cost an estimated $8 billion a year to maintain. That is a sum far beyond the means of the Kabul government, whose annual domestic revenue is about $2 billion.

Without a clear plan for paying for ongoing costs, the commission says, army bases, police stations, border outposts and other facilities built by the United States at a cost of $11.4 billion since 2005 could be at risk.

The Pentagon has received $35 billion from Congress to train and equip the Afghan security forces. The Obama administration is seeking an additional $12.8 billion for fiscal 2012 to continue that effort, which involves expanding the total force to 352,000 personnel.

Senior U.S. government officials have said that the United States will have to foot much of the bill for sustaining the Afghan forces. They maintain that doing so, even at a cost of $8 billion a year, is far cheaper than keeping large numbers of U.S. troops on Afghan soil.

But the commission’s other chairman, Michael Thibault, former deputy director of the Defense Department’s contract audit agency, warned that the military command responsible for training Afghan forces has not established an adequate oversight plan to ensure that U.S. funds will not be misspent once American troops step back from combat operations in 2014.

“Who is going to audit and award these contracts? Who is going to protect the interests of the American taxpayer to ensure these billions and billions of dollars are awarded appropriately?” Thibault said. “We believe the potential for waste is much more significant going forward.”

A spokesman for the training command could not be reached for comment. U.S. military officials have previously said that they intend to design oversight mechanisms before funneling money directly through the Afghan Defense Ministry.

The commission also cited a $300 million power plant, completed last year by USAID near Kabul, that sits idle most of the time because the Afghan government has been able to buy electricity from neighboring Uzbekistan at a fraction of the cost. The plant, the commission writes, stands “as an example of poor planning and waste.”

Anderson, the USAID spokesman, said the agency could not comment on the commission’s statements about the power plant without seeing the report.