The Senate voted Wednesday to reduce the United States' share of the cost of U.N. peacekeeping missions (search) by tens of millions of dollars.

The vote reflected congressional criticism of the United Nations following allegations of corruption and mismanagement in the Oil-for-Food (search) program for Iraq, sexual abuses by peacekeepers and other scandals.

U.S. dues are now capped at 27.1 percent of the peacekeeping budget. Under a 1994 law, that cap is to be reduced to 25 percent.

The Bush administration — with the support of Democrats — asked that the cap be maintained at 27.1 percent. A Democratic proposal to keep the higher cap was defeated in a 57-40 vote, mostly along party lines.

The United States is expected to spend about $1 billion on peacekeeping operations this year, with much of the money for activities in Sudan (search) and Haiti (search). The administration is seeking about the same amount for next year.

If the cap were reduced, that could result in roughly a $75 million peacekeeping cut.

The vote came as an amendment to a bill authorizing $34 billion in spending on foreign aid and State Department operations for 2006. The figure generally reflects Bush's spending request and is about 13 percent more than current spending.

Prospects for the overall bill becoming law are unclear. No foreign aid authorization bill has been passed since 1985, according to Senate staff, largely because of disputes related to abortion policies and other issues. The actual funding for foreign aid comes from separate spending bills.

In arguing to allow the 25 percent cap to become law, Republican senators said this would strengthen the hand of U.S. diplomats as they negotiate the U.S. share of peacekeeping expenses and push for reforms at the United Nations.

Senate Majority Leader Bill Frist warned that if the Democratic proposal were adopted, "we will make that job more difficult by conceding our willingness to live with the status quo."

But Sen. Joseph Biden, the top Democrat on the Foreign Relations Committee, said the 25 percent cap could lead to the United States falling behind in its U.N. dues, as it did in the 1990s. He said it would compound problems caused by Bush's nomination of John Bolton, a sharp critic of the United Nations, to become the new U.N. ambassador, he said.

"The double whammy of sending Bolton to the U.N. and cutting our commitment ... would be a very serious problem," he said.

The House has not yet taken up its version of the bill. It is expected to include provisions calling for greater openness and other changes at the United Nations.