ISLAMABAD, Pakistan — A provincial court on Thursday gave the Pakistani government three weeks to decide whether the American official in custody for killing two Pakistanis has diplomatic immunity, a delay that is likely to intensify a standoff with the United States, the nation’s biggest donor and an ally in the fight against terrorism.
The decision came a day after a whirlwind visit by Senator John Kerry to try to find a quick resolution to the case, which has severely damaged relations between the countries and exposed the weakness of the pro-American government headed by President Asif Ali Zardari.
The public furor in Pakistan has revolved around why Raymond A. Davis, 36, arrested with a loaded Glock handgun and other security gear, was driving alone in an impoverished area of Lahore not usually frequented by diplomats. After Mr. Davis killed two motorcyclists who he said were trying to rob him, an official American car that tried to rescue him ran over another motorcyclist, who later died. That car fled the scene.
In an argument before the court in Lahore, the advocate general of Punjab Province, Khawaja Haris, said the authorities had filed a “double murder case” against Mr. Davis.
On the matter of diplomatic immunity, which the Obama administration insists on, the lawyer pointed to conflicting statements by the Americans on the status of Mr. Davis.
On Jan. 27, the day of the shooting, the United States Consulate in Lahore issued a statement saying Mr. Davis was an employee of the consulate and the holder of a diplomatic passport.
Later, the American Embassy in Islamabad said Mr. Davis, a former Special Forces soldier, worked at the embassy and was employed as a “technical and administrative” official.
The application sent to the Pakistani Foreign Ministry in late 2009 for Mr. Davis’s posting to Pakistan stated that he would work as a “technical and administrative” official at the embassy.
The distinctions could have a bearing on the outcome, since the Vienna Conventions, the international protocols under which diplomatic immunity is regulated, have different standards of immunity for officials employed at embassies and at consulates.
The Obama administration insists that Mr. Davis’s status as a “technical and administrative” official, a phrase used in the 1961 Vienna Convention, grants him immunity from prosecution. The administration has repeatedly said that Mr. Davis is being held illegally and must be released.
President Obama, speaking at a news conference this week, referred to Mr. Davis as “our diplomat.”
Officials assigned to consulates generally enjoy less immunity from prosecution in the host countries, according to lawyers who specialize in diplomatic law.
The judge in Lahore, Chief Justice Ijaz Ahmad Chaudhry, ordered the Foreign Ministry to present its findings on Mr. Davis’s immunity in three weeks, further frustrating the Obama administration’s effort to win his speedy release.
In a statement after the court proceedings, the American ambassador, Cameron Munter, said the United States was disappointed that the Pakistani government had not certified that Mr. Davis had diplomatic immunity.
To press Pakistan, the Obama administration has postponed a meeting scheduled for later this month in Washington where officials from Pakistan, Afghanistan and the United States were to discuss the war in Afghanistan.
It has also warned Pakistan that a planned state visit by Mr. Zardari next month would be in jeopardy if the case was not resolved, and Congress has threatened to cut military assistance.
The argument by Mr. Haris before the court echoed the hard line taken by former Foreign Minister Shah Mehmood Qureshi. Mr. Qureshi lost his job in a cabinet reshuffle last week because he said he refused to issue the “blanket immunity” for Mr. Davis demanded by the United States, and favored by President Zardari and his close advisers.
Senator Kerry, the chairman of the Senate Foreign Relations Committee and the sponsor of a $7.5 billion aid package for Pakistan, left Pakistan on Wednesday night after meeting with top leaders, including President Zardari. He was confident, he said, that the Davis case would be resolved in the “next few days.”
Mr. Kerry met with Mr. Qureshi and the leader of the main opposition party, Nawaz Sharif, the most powerful politician in Punjab. After those meetings, Mr. Qureshi and Mr. Sharif did little to help the Americans to win Mr. Davis’s release, suggesting that the courts should decide the case.
Mr. Qureshi, who had refused to declare Mr. Davis a diplomat entitled to “blanket immunity,” denied at a news conference that he was influenced by the Pakistani military in his decision.
Mr. Sharif criticized the United States for not handing over the people in the car who tried to rescue Mr. Davis, saying that Pakistani officials had written five letters to the consulate in Lahore demanding to know their whereabouts. The consulate had not replied, he said.
Mr. Davis is being held at the central jail in Lahore, where American officials say he is sleeping on a foam mat on a concrete floor without access to a cellphone, the Internet or television.
Video showing Mr. Davis declining to answer questions while in custody has been shown on the television channel Express News.
Apparently leaked from law enforcement authorities supervising Mr. Davis’s custody, the video shows Mr. Davis dressed in a blue jersey, impatiently getting up from a chair and indicating that he would not cooperate.
After the High Court hearing on Thursday, Mr. Davis appeared in a video link from the Lahore jail for a hearing in a lower court to extend his remand for 14 more days on a separate charge involving his carrying the Glock pistol. The authorities charge that Mr. Davis was armed illegally.
Waqar Gillani contributed reporting from Lahore.