Budget constraints may kill the Bush administration's efforts to pay off more than a half-billion dollars in arrears to the United Nations and other international bodies.

The State Department asked Congress on Monday to approve the debt payment plan as a strong signal of support for internal U.N. reforms and for the organization's authorization of allied military action that ended Iraq's occupation of Kuwait.The administration asked that the arrears payments be appropriated for fiscal 1992 and then paid off in four annual installments.

But a congressional subcommittee chairman who oversees State Department expenditures said the money probably could not be authorized in advance.

Rep. Neal Smith, D-Iowa, said at a House Appropriations subcommittee hearing that the administration's plan likely would exceed budget ceilings agreed upon last year by President Bush and congressional leaders.

Smith said Congress may be precluded from approving more than one year's payment of arrears.