The United States called on its close ally Israel on Tuesday to conduct credible investigations into allegations of war crimes committed by its forces in Gaza, saying it would help the Middle East peace process.

Click here for more on the Goldstone report on Gaza

Michael Posner, U.S. Assistant Secretary of State, said that Hamas leaders also had a responsibility to investigate crimes and to end what he called its targeting of civilians and use of Palestinian civilians as human shields in the strip.

The UN Human Rights Council was holding a one-day debate on a recent report by Richard Goldstone, a South African jurist and former U.N. war crimes prosecutor.

His panel found the Israel Defense Forces and Palestinian militants committed war crimes and possibly crimes against humanity during their December-January war. Israel did not cooperate with the UN inquiry and has rejected the report as biased.

"We encourage Israel to utilize appropriate domestic [judicial] review and meaningful accountability mechanisms to investigate and follow-up on credible allegations," Posner said in a speech to the Geneva forum.

"If undertaken properly and fairly, these reviews can serve as important confidence-building measures that will support the larger essential objective which is a shared quest for justice and lasting peace," he said.

The United States joined the Council, set up three years ago, for the first time earlier this year.

Posner reiterated Washington's view that the Council paid "grossly disproportionate attention" to Israel, but said that the U.S. delegation was ready to engage in balanced debate.

Goldstone: Impunity for war crimes impedes Mideast peace

Goldstone told a news conference on Tuesday it was encouraging that the United States "has called for acceptable investigations of the allegations by both sides. I think that's important support."

Earlier, he said a lack of accountability for war crimes committed in the Middle East had reached "crisis point", undermining any hope for peace in the region.

"A culture of impunity in the region has existed for too long," Goldstone, a former UN war crimes prosecutor, told the UN Human Rights Council.

"The lack of accountability for war crimes and possible war crimes against humanity has reached a crisis point; the ongoing lack of justice is undermining any hope for a successful peace process and reinforcing an environment that fosters violence."

Goldstone also called on Israel and Hamas to conduct open and credible investigations into atrocities during the December-January conflict in the coastal strip.

Israel's stated goal in the 3-week campaign was the cessation of cross-border rocket attacks by Gaza militants, which had plagued the country's south for eight years.

Israel says 1,166 Palestinians were killed in the offensive, the majority of whom were militants. Human rights groups say, however, that approximately 1,400 Palestinians were killed, mostly civilians. Thirteen Israelis were killed during the fighting: ten soldiers and three civilians.

Goldstone urged the 47-member state forum to adopt his panel's recent report which found that the Israel Defense Forces and Palestinian militants committed war crimes and possibly crimes against humanity during the hostilities. Adoption of the report would mean it is referred to the UN Security Council for further action.

The jurist acknowledged that the four-member panel had been hit with a "barrage of criticism" on its findings, but said the investigation had not been politically motivated.

"We believe deeply in the rule of law, humanitarian law, human rights and the principle that in armed conflict civilians should to the greatest extent possible be protected from harm, he told the UN body.

He added that it was important not to ascribe collective guilt to a people. "People of the region should not be demonized," Goldstone said.

Israeli and Palestinian delegations are due to address the Geneva forum, which is holding an all-day debate on the report before considering resolutions on the issue later this week.