The trial of Raymond Davis, the CIA agent facing charges of double murder in Pakistan, has started amid tight security and some secrecy in a Lahore jail.
The press and public have excluded from the trial in Kot Lakhpat jail, where Davis has been held since he shot dead two men on a busy Lahore street on 27 January.
Raymond Davis. Photograph: Arif Ali/AFP/Getty Images US embassy spokeswoman Courtney Beale confirmed that a sessions court hearing was taking place on Friday but said the full trial would not start until Pakistani prosecutors pressed formal charges.
The US consul general in Lahore, Carmela Conroy, was present at the hearing.
The Davis case has sparked a crisis between Pakistan and the US, prompting meetings between top intelligence and military leaders in both countries in recent days.
On Tuesday Pakistan's top brass, led by army chief General Ashfaq Kayani, met a delegation of American generals led by Admiral Mike Mullen at a luxury resort in Oman to discuss the matter.
The US side stressed that it "did not want the US-Pakistan relationship to go into a freefall under media and domestic pressures", according to an account of the meeting obtained by Foreign Policy magazine.
Pakistan's intelligence agency, the Inter-Services Intelligence (ISI), has made judicious media leaks to help stir public anger towards Davis. They have included the release of documents this week that made unprecedented criticism of the CIA, suggesting the relationship is near breaking point.
US intelligence has also exerted pressure, claiming that Davis is in mortal danger at Kot Lakhpat jail and restarting the campaign of CIA drone strikes in the tribal belt that had stopped on 23 January.
There have been almost daily drone strikes since Monday – the CIA's way of "showing who's in charge", admitted one senior Pakistani official. At the Oman meeting Mullen told Kayani he could apply "other levers" if a solution to the case was not found, the official said.
The backroom manoeuvring takes place against a backdrop of public outrage in Pakistan, where militant and religious groups have launched noisy street protests calling for the hanging of Davis, a 36-year-old former special forces soldier.
The anger is driven by outrage that an armed American could open fire in the country's second-largest city, killing two people with 10 bullets. American claims that Davis has diplomatic immunity are legally contested and enjoy little public sympathy.
Religious groups and some political parties are putting pressure on the families of the two men Davis killed not to accept compensation from the US government – a solution that US officials quietly favour.
The papers have been filled with lurid accounts of Davis's activities in Pakistan, with some alleging he was linked to the Taliban or served as the acting head of the CIA in Pakistan – unlikely tales apparently designed to step up pressure on the Americans.
There has been little focus, however, on the activities of the two men Davis killed, variously described as robbers or intelligence operatives. A senior ISI official has told the Guardian that the agency suspects Davis knew the men.
In a separate case to decide the issue of diplomatic immunity, the government is due to present its report on Davis's diplomatic status to the Lahore high court on 14 March.
A senior retired state department lawyer told the Guardian and Slate.com that the US argument for immunity appeared to be weak in Davis's case.