The Bush administration dropped its plan Wednesday to seek renewal of a U.N. resolution shielding U.S. personnel serving in U.N.-authorized peacekeeping missions from prosecution by the International Criminal Court, citing fierce opposition to the initiative.

The retreat represented the most significant defeat for the United States in the Security Council since March 17, 2003, when U.S. officials abandoned a bid to win support for a resolution authorizing the U.S.-led war against Iraq.

It also marked the most concrete evidence of a diplomatic backlash against the scandal over abuse of U.S. detainees in Afghanistan and Iraq. The exemption for U.S. officials has spurred resentment since the Security Council first granted it, in July 2002, but Security Council diplomats said the detainee abuse provided a rallying point for supporters of the court.

The practical impact of Wednesday's retreat was mitigated by the United States' signing of agreements with 90 countries not to surrender U.S. personnel to the court. But it raised the possibility, albeit limited, that U.S. troops accused of massive human rights violations while serving in U.N.-authorized operations could be brought before the world court after the current resolution expires on July 1.

The U.S. decision followed an attempt on Tuesday to gain support by limiting the renewal to one year, rather than annually "for as long as may be necessary," as the current resolution states.

"We believe our draft and its predecessors fairly meet the concerns of all," James B. Cunningham, the acting U.S. ambassador to the United Nations, said after informing the council of the decision. "Not all council members agree, however, and the U.S. has decided not to proceed further with consideration of action on the draft at this time in order to avoid a prolonged and divisive debate."

The withdrawal represented a major victory for the strongest court advocates on the Security Council, including France and Germany. Several council members insisted that their refusal to support the U.S. resolution reflected their support for the court. "This was not a vote against the United States," said Heraldo Munoz, Chile's U.N. ambassador.

Others, however, noted that the detainee abuse scandal, combined with Washington's need for support of its Iraq policy, had undermined the U.S. policy of threatening to shut down U.N. peacekeeping missions if the council did not grant U.S. officials immunity.

"Their capacity for retaliation has been diminished. It has been weakened," said a senior council ambassador, who requested anonymity because he did not want to offend the United States. "They now need the United Nations."

The court was established by a 1998 treaty to prosecute individuals responsible for the most serious crimes, including genocide, war crimes and crimes against humanity. The office of the court's chief prosecutor, Luis Moreno Ocampo of Argentina, on Wednesday announced its first investigation, into reports of "thousands of deaths by mass murder and summary execution" in the Democratic Republic of Congo since July 2002.

Since the court began its work that month, the Security Council has twice grudgingly adopted a U.S.-sponsored resolution exempting U.S. personnel from prosecution.

The resolution grants immunity to "former or current officials" from countries that have not ratified the 1998 treaty, which include the United States, China and Russia. Afghanistan has ratified the treaty but has signed an agreement with the United States not to hand over U.S. personnel to the court. Iraq has not ratified the treaty.

The Bush administration was confident last month that it had lined up the nine votes needed to renew the resolution in the 15-nation council. But the U.S. initiative began to unravel when nations whose support the United States expected, such as Chile, indicated they would abstain.

The United States postponed plans to put its resolution to a vote in late May after China warned that it was considering abstaining or even vetoing the resolution. At the time, the Chinese cited concern over detainee abuses, but U.S. and other Security Council officials said that China had intervened to punish the United States for backing Taiwan's bid for observer status in the World Health Assembly.

Last Thursday, Secretary General Kofi Annan appealed to the council to oppose the resolution, saying that it would "discredit" the United Nations and undercut its promotion of the rule of law.

The moves emboldened other council members, including Russia and Algeria, to reconsider their support for the resolution.

The United States had secured assurances of support from only four other council members -- Britain, Angola, Pakistan and the Philippines -- when it decided to withdraw its text from consideration.