The forecast includes the cost of keeping some U.S. forces in Iraq for several years and of providing long-term care and financial support for wounded soldiers and benefits for the families of those killed, the Boston Globe reported.

"We are now spending on these activities more than 10 percent of all the government's annually appropriated funds," Robert A. Sunshine, the assistant director for budget analysis, said Tuesday.

The government has already allocated $500 billion for combat operations and reconstruction.

In 2003, the Bush administration gave far lower estimates for the war, assuming a quick military operation and restoration of Iraq's oil industry to pay for rebuilding. A White House budget analyst was fired for predicting that the war could cost $200 billion.