WASHINGTON, July 26 — Three years after President Bush urged global rules to stop additional nations from making nuclear fuel, the White House will announce on Friday that it is carving out an exception for India, in a last-ditch effort to seal a civilian nuclear deal between the countries.

The scheduled announcement, described Thursday by senior American officials, follows more than a year of negotiations intended to keep an unusual arrangement between the countries from being defeated in New Delhi.

Until the overall deal was approved by Congress last year, the United States was prohibited by federal law from selling civilian nuclear technology to India because it has refused to sign the Nuclear Nonproliferation Treaty. The legislation passed by Congress allows the United States to sell both commercial nuclear technology and fuel to India, but would require a cutoff in nuclear assistance if India again tests a nuclear weapon. India’s Parliament balked at the deal, with many politicians there complaining that the requirements infringed on India’s sovereignty.

Under the arrangement that is to be announced by Secretary of State Condoleezza Rice, Mr. Bush has agreed to go beyond the terms of the deal that Congress approved, promising to help India build a nuclear fuel repository and find alternative sources of nuclear fuel in the event of an American cutoff, skirting some of the provisions of the law.