A U.N. investigator defended a report Tuesday that accuses Israel and Palestinian militants of war crimes during their conflict in Gaza, an allegation Israel condemns and claims is the result of bias against the Jewish state.

Former South African Judge Richard Goldstone said he and his fellow investigators rejected criticism by Israel that the 575-page report was 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 U.N. Human Rights Council before a debate on the report.

Goldstone said his team was motivated by a desire to hold accountable those on both sides who harmed civilians in violation of international law.

Israeli Ambassador Aharon Leshno-Yaar described the report as "shameful," claiming it cherry-picked incidents during the Dec. 27-Jan. 18 conflict for political effect, ignored Israel's right to self-defense, and provided "support and vindication for terrorist tactics."

The Palestinian ambassador in Geneva, Ibrahim Khraisha, welcomed the report and said it was an "objective" account of what had happened in Gaza.

Almost 1,400 Palestinians were killed — many of them civilians — during Israel's three-week military operation against Palestinian rocket squads firing at southern Israel. Thirteen Israelis also died, including four civilians.

The report investigated 36 incidents and interviewed dozens of Palestinian and Israeli witnesses in Gaza and Geneva. Israel's refusal to cooperate with the investigators prevented them from visiting Israel.

The report examined one case in which Israeli forces allegedly shelled a house where soldiers had forced Palestinian civilians to assemble, and seven incidents in which civilians were shot while leaving their homes trying to run for safety.

On the Palestinian side, the report found that armed groups firing rockets into southern Israel from Gaza failed to distinguish between military targets and the civilian population, and collected several reports of Palestinians being held as human shields by militants.

A resolution by Arab and Muslim countries proposes endorsing the report, including a recommendation that it be referred to the powerful U.N. Security Council in order to require both sides to show they are carrying out credible investigation into alleged abuses during the conflict.

If either side refuses, the investigators recommend that the Security Council pass evidence to prosecutors at the International Criminal Court, the world's first permanent war crimes tribunal, within six months.

"Israel is committed to fully examining every allegation of wrongdoing, not because of this report, but despite it," Leshno-Yaar told the council.

Goldstone, however, has called Israel's efforts so far "pusillanimous." He also described investigations by the Palestinian group Hamas, which controls Gaza, as a "complete failure."

European nations on the 47-member rights council cautiously welcomed the report, but diplomats have made clear they don't support all of its findings and are critical of how the document was compiled.

The U.S., which took part as a member for the first time in the council's three-year existence, also criticized the report.

"We disagree sharply with many of the report's assessments and its recommendations and believe it to be deeply flawed," U.S. Assistant Secretary of State Michael H. Posner said.

Washington also rejects the suggestion that the allegations be taken up by the Security Council in New York.

"If this standard were applied in every conflict situation around the world where there are alleged violations, then the role of the Human Rights Council would be dramatically different," he said.