After weeks of debate on the Iraqi prisoner abuse scandal, nuclear weapons and plans for a missile defence system, the US Senate unanimously passed a $447 billion bill for defence programmes including operations in Iraq and Afghanistan.

The bill, approved 97-0, gives President George W. Bush most of what he wanted, including $25 billion for military operations in Iraq and Afghanistan.

Republicans fended off final amendments from Democrats, defeating a bid to force the administration to release documents on its treatment of enemy combatants in the wake of the scandal over sexual and physical abuses of Iraqi prisoners.

After bitter partisan debate, the Senate voted 50-46 to kill the measure demanding Attorney General John Ashcroft turn over documents on the interrogation and treatment of prisoners in Iraq, Afghanistan and Guantanamo Bay, Cuba.

Republicans also defeated a plan to expand prescription drug and health services for veterans that would have cost $300 billion over 10 years, and a measure requiring the White House to give Congress an estimate of the number of US troops it expects to have in Iraq by the end of 2005.

Republicans said the veterans care measure was too costly, and that the White House could not estimate troop requirements in Iraq a year from now.

"Political developments in Iraq will drive security estimates so we cannot determine now what our needs are going to be," said Senator Mitch McConnell, a Kentucky Republican.

But Senator Edward Kennedy, a Massachusetts Democrat, said with next week's transfer of sovereignty in Iraq, "American families are entitled to know how long their sons and daughters are going to serve in Iraq."

The Senate agreed to continue an independent inspector general's office to oversee US-financed reconstruction contracts after the US provisional government in Iraq transfers power to an interim Iraqi government next week.

In debate spread over three to four weeks, the Senate defied the Pentagon and voted overwhelmingly to boost the Army by 20,000 troops to relieve stress on soldiers forced into extended duty in Iraq and Afghanistan.

But in most votes, Republicans defeated Democrats' amendments including attempts to block the administration's research on a new generation of earth-penetrating and low-yield nuclear weapons, and to require more stringent tests of a missile intercepting system the administration plans to deploy this year.

The Senate's bill to authorise defence and nuclear weapons programmes is up 3.4 per cent from current levels, excluding the $25 billion in emergency funds it authorises for Iraq and Afghanistan operations.

The House has passed its version of the bill, as well as a defence appropriations bill that provides the money for the programmes.