The United States hopes to use the U.N. Human Rights Council to engage other countries in a dialogue on universal values, senior U.S. State Department officials said Monday.

They also called Washington's membership in the body an "experiment" ahead of a sensitive debate on Tuesday about last year's Gaza war.

The U.S. sees its role in the U.N. Human Rights Council — which was spurned by the previous U.S. administration for its excessive criticism of Israel — as part of a wider effort to engage the U.N. and the Arab world, said State Department legal adviser Harold Koh. He said universal agreement on all human rights issues was unlikely among the council's 47 members.

"We think that this is a forum, the Human Rights Council, where those three principles, engagement, universality and the truth, can be explored," Koh told journalists in Geneva.

The Obama administration joined the council earlier this year, after it was largely ignored by Washington in its first three years of existence.

"It's an experiment," Koh said.

The first real test comes Tuesday when the council examines a report that alleges Israel committed war crimes during its Dec. 27-Jan. 18 military operations against Palestinian rocket squads in Gaza.

The U.S. position is complicated as officials in Washington already have rejected parts of the report of the U.N. expert group, led by former South African Judge Richard Goldstone and lauded by human rights campaigners as one of the most balanced and constructive U.N. probes in recent memory.

New York-based Human Rights Watch called Monday for the administration to reverse its position and endorse the report, which also called Hamas' firing of rockets at Israeli civilians a war crime.

"The Obama administration cannot demand accountability for serious violations in places like Sudan and Congo but let allies like Israel go free," said Sarah Leah Whitson, Human Rights Watch's Middle East director.

Koh and U.S. Assistant Secretary of State Michael H. Posner, who will represent the U.S. on Tuesday, declined to comment directly on Washington's position ahead of the Gaza debate. But they acknowledged that the outcome may be the first of several council actions that aren't to America's liking.

"How the council develops as an institution and what constructive role we can play in that development remains to be seen," said Koh. "We have principles, and we have hopes, and that's how we're pursuing this."