US officials regard European human rights standards as an "irritant", secret cables show, and have strongly objected to the safeguards which could protect WikiLeaks founder Julian Assange from extradition.

In a confidential cable from the US embassy in Strasbourg, US consul general Vincent Carver criticised the Council of Europe, the most authoritative human-rights body for European countries, for its stance against extraditions to America, as well as secret renditions and prisons used to hold terrorist suspects.

He blamed the council for creating anti-US sentiment and hampering the US war on terror. "The Council of Europe (COE) likes to portray itself as a bastion of democracy, a promoter of human rights, and the last best hope for defending the rule of law in Europe – and beyond," Carver said. "[But] it is an organisation with an inferiority complex and, simultaneously, an overambitious agenda.

"An investigation [by the Council of Europe] into renditions and 'secret prisons' in Europe connected to the US war on terrorism … created a great deal of controversy and anti-US sentiment in the Council of Europe," wrote Carver.

The European court of human rights, the final court of appeal for human rights claims from the UK, whose judgments include the decision to ban deportations to countries which practise torture, is also singled out by the cables.

"The European court of human rights … has also requested more information on pending British extradition cases to the US where it believes the prisoners might be sentenced in the US to life imprisonment with no possible appeal or automatic judicial review of the life sentence," Carver wrote.

Amid growing speculation over whether Assange could face extradition to the US, the cables make clear America's opposition to any attempts to interfere on human rights grounds, out of concern for prison conditions in the country.

Assange would have the right to appeal against any extradition decision to the European court of human rights if all other legal avenues failed. His lawyers are already forming human rights arguments to block his extradition within the EU.

The cables also single out high-profile individuals within the Council of Europe for criticism, in particular British secretary general Terry Davis – now retired – who is described by the Americans as an "unpopular lame duck.

"Terry Davis leaves office this summer, after a five-year term that has been, according to many sources, devoid of vision," Carver wrote in 2009.

"Davis is known as a micro-manager and will not be missed by many of his staff as well as by many resident ambassadors." Davis provoked the wrath of American officials through his outspoken attacks on secret renditions.

The cables show that US diplomats wanted to visit his successor, current secretary general Thorbjørn Jagland, to persuade him to refrain from similar public criticism of the US.

"Jagland can be expected to criticise the US for the death penalty; he may, however, be less enthusiastic than the previous secgen, Terry Davis, in publicly criticising renditions, particularly if we review such issues with him soon," Carver wrote.

"In this regard, we highly recommend a visit by a ranking department official ... to review our human rights agenda with the new secretary general in the next several weeks."

News that the Americans sought to pressure Jagland, the former prime minister of Norway, to prevent him from criticising secret renditions is likely to anger many in Europe, who see the council's role in protecting human rights from counter-terrorism policy as crucial.

But the Americans also reserved judgment on Thomas Hammarberg – the council's human rights commissioner – for his criticism of US counter-terrorism policy. In a separate cable referring to comments made to the US by the Maltese ambassador, Hammarberg is accused of seeing himself as "God's gift to the world".

The cables also reveal the pettiness of diplomatic exchanges within the Council of Europe.

In one exchange the US noted "a rather sad exchange" where Greece complained that Hammarberg had chosen photos of Turkey for his website that portrayed a positive image of the country.

"The Greek ambassador criticised photos apparently chosen for Hammarberg's website regarding [his] recent official visit to Turkey," Carver wrote. "The Greek contrasted the 'vacation-like, very positive' images with those associated with the commissioner's visit to Greece."