Julian Assange says claims in leaked documents yet to be investigated, as US faces UN grilling over human rights record

The founder of whistleblowing website WikiLeaks has called on the US to investigate alleged abuses by its troops in Afghanistan and Iraq, saying it has a "proud tradition" of self-scrutiny.

Julian Assange says the US has not started any investigations into the alleged incidents detailed in thousands of documents published by WikiLeaks and has instead concentrated on tracking down those responsible for the leaks and on hounding his group.

Last month, WikiLeaks published 400,000 US field reports containing evidence that US soldiers handed over detainees to a notorious Iraqi torture squad. This followed a the publication of 75,000 documents in the summer revealing how coalition forces killed hundreds of civilians in unreported incidents in Afghanistan.

Assange made his comments ahead of a big diplomatic set piece in Geneva tomorrow, when America's human rights record comes under scrutiny before the UN human rights council for the first time. Every UN member is subject to what is called a universal periodic review every four years. The US is taking its moment under the spotlight seriously, sending a high-level delegation of some 30 officials to fend off expected attacks in a forum dominated by developing countries, many of them Muslim.

Iran has already begun sniping at the US. Earlier this week an Iranian foreign ministry official said Tehran was concerned about violations of human rights in western countries, particularly in the US.

"We are seriously concerned about the human rights situation in western countries and will bring up our points during the UN human rights council universal periodic review conference," said Ramin Mehmanparast, an Iranian foreign ministry spokesman.

In anticipation of criticism from countries such as Iran, the US said it was open to fair criticism of its record, while former senior American officials warned of political fireworks.

"There should be no illusions: the council is a highly political environment, and there is bound to be strong criticism of the United States on specific matters," said a comment piece in the New York Times co-written by Thomas Pickering, the former US ambassador to the UN.

While the US may brush aside attacks from the likes of Iran and Bolivia as highly partial, it cannot so lightly dismiss concerns from allies and friends. Britain, Japan, Norway have all raised concerns about the death penalty in the US.

"The UK remains concerned about the continuing use of the death penalty in the US, and particularly by evidence that the death penalty is administered in an arbitrary and discriminatory manner with an inevitable risk of miscarriages of justice," Britain said in a question submitted to the US. "Could you tell us what steps the administration is taking to address these concerns?"

Another pithy British question likely to make the Obama administration uncomfortable said: "Could you please outline the next steps needed to ensure the final closure of the detention facility in Guantánamo?"

Human rights groups have also piled in with their submissions. More than 300 activist groups, including Amnesty International and the American Civil Liberties Union, have issued a separate 400-page report claiming that protection of fundamental freedoms has eroded since 9/11.

"Human rights advocates across America have not only documented substandard human rights practices which have persisted in the US for years, but also those that reflect the precipitous erosion of human rights protections in the US since 9/11," said Sarah Paoletti of the US human rights network.

"Whether it is migrant labourers who are excluded from workplace protections, children denied education because of the school-to-prison pipeline, or women denied equal pay in the workplace, advocates feel compelled to bring their experiences before international human rights mechanisms because the US legal system has fallen short."

A state department submission in August, written after extensive public consultation, said American was a democracy guided by "simple but powerful principles", but admits to discrimination against black people and Hispanics and a "broken" immigration system.

The US said it was at "currently at war with al-Qaida and its associated forces" but that it would comply with all applicable domestic and international law in armed conflicts and had ordered foreign detainees be treated humanely.

It pointed to a "free, thriving and diverse independent press", said it upheld freedom from religious persecution and had worked to ensure fair treatment of Muslims, Arab-Americans and South Asian communities affected by discrimination and intolerance since 9/11. It acknowledged concerns about the US justice system including capital punishment, juvenile justice, racial profiling and racial disparities in sentencing.

The UN general assembly created the 47-member human rights council in 2006 after its predecessor, the UN human rights commission, was discredited as a politicised forum which gave a platform to regimes with dismal human rights records.