"Human rights are an essential element of American global foreign policy," Secretary of State Hillary Rodham Clinton said in a statement. "With others, we will engage in the work of improving the U.N. human rights system. . . . We believe every nation must live by and help shape global rules that ensure people enjoy the right to live freely and participate fully in their societies."

The United States announced it would participate in elections in May for one of three seats on the 47-member council, joining a slate that includes Belgium and Norway.

New Zealand, which had also been on the ballot, supports the U.S. decision and withdrew its name to make room for the United States, Foreign Minister Murray McCully announced. "Frankly, by any objective measure, membership of the Council by the U.S. is more likely to create positive changes more quickly than we could have hoped to achieve them," he said.

The decision was welcomed by U.N. officials and rights advocates, who had been briefed on the decision. Human rights activists have been advocating U.S. membership in the council since its creation in March 2006.

"This is a welcome step that gives the United States and other defenders of human rights a fighting chance to make the institution more effective," said a human rights advocate familiar with the decision. "I think everybody is just desperate to have the United States and Barack Obama run for the human rights council, and countries are willing to bend over backward to make that happen."

The Geneva-based Human Rights Council was established in March 2006 to replace the 60-year-old Human Rights Commission, which lost international credibility after countries with abysmal rights records, such as Sudan and Zimbabwe, were allowed to join and thwart criticism of their actions.

The Bush administration refused to join the new rights body, saying it was not convinced that it represented much of an improvement over its predecessor. John R. Bolton, U.S. ambassador to the United Nations when the council was created, said at the time that the United States would have more "leverage in terms of the performance of the new council" by not participating in it and thus signaling a rejection of "business as usual."

Reached Tuesday, Bolton denounced the Obama administration's decision. "This is like getting on board the Titanic after it's hit the iceberg," he said. "This is the theology of engagement at work. There is no concrete American interest served by this, and it legitimizes something that doesn't deserve legitimacy."

The Obama administration and rights advocates concede that the Human Rights Council has failed to emerge as a powerful champion of human rights, saying it has devoted excessive attention to alleged abuses by Israel and too little to abuses in places such as Darfur, Sri Lanka and Zimbabwe.

Last week, the rights council adopted a resolution sponsored by Pakistan and other Islamic states that condemns the "defamation of religion" as a violation of human rights, arguing that abuses against Muslims have mounted in the years following the 911 terror attacks. But European states criticized the Islamic resolution, saying it posed a threat to the right of free speech. However, the decision to seek a seat on the council is in keeping with what President Obama has called a "new era of engagement" with other nations to advance U.S. security interests and meet the global challenges of the 21st century.

Susan Rice, the U.S. ambassador to the United Nations, said: "Those who suffer from abuse and oppression around the world, as well as those who dedicate their lives to advancing human rights, need the council to be balanced and credible." She said the United States seeks election to the body "because we believe that working from within, we can make the council a more effective forum to promote and protect human rights."

The Human Rights Council is an inter-governmental body within the U.N. system made up of 47 elected members whose mission is to strengthen the promotion and protection of human rights globally. The next round of elections to the council will be held May 15 in the U.N. General Assembly in New York, with members elected to three-year terms. The council is scheduled to undergo a formal review of its structure and procedures in 2011, offering an opportunity for reform.