Feb. 14, 2011  -- The spokesperson for Pakistan's ruling party invoked the Vienna Convention and diplomatic immunity for the first time today as a possible avenue for the U.S. to secure the release of Raymond Davis, the American diplomat who allegedly gunned down two Pakistani men last month.

Fauzia Wahab, a spokesperson for the Pakistan People Party, said that no diplomat can be kept in captivity and that Davis has an official diplomatic visa. The U.S. State Department has been demanding Davis' release based on the same points since the Jan. 27 shooting incident, but today marks the first time a prominent Pakistani official publicly backed the international agreement in Davis' case.

Wahab's comments come just a day after the Taliban issued a threat on the lives of anyone involved in Davis' release.

"Whether he is a judge, police, lawyer, army, policy maker or a politician, we will target him. We will kill him," a Taliban spokesman told The Associated Press Sunday.

Davis, 36, was arrested after allegedly shooting and killing two men on the streets of Lahore, Pakistan, who the U.S. State Department said were trying to rob him. A third Pakistani man was struck and killed by a vehicle that was reportedly racing to Davis' aid. U.S. officials have repeatedly declined to answer questions about Davis' precise job in Pakistan, saying only he was a "member of the administrative and technical staff" of the Islamabad embassy and traveled on a diplomatic passport. Public records show Davis has experience with the U.S. Special Forces and runs a small security company.

Despite holding a diplomatic passport, Davis has been held in Lahore since the incident and Lahore's police chief Friday rejected the idea he had acted in self-defense. The shooting was "intentional and cold-blooded murder," police chief Aslam Tareen said.

After the court's decision to detain Davis for an extended period Friday, Carmela Conroy, the U.S. Consul General in Lahore, said that the incident was a tragedy, and extended her sympathy to the family of the men killed, but said that Davis is "entitled to full immunity from prosecution" as a member of the U.S. Embassy staff in Islamabad.

"Under the rules, he should be freed immediately," said Conroy, who visited Davis in prison last week. She also said she regretted that authorities "did not consider ... eyewitness accounts and physical evidence" that indicated Davis acted in self defense.

Ray Davis and Diplomacy: Caught Between America and Pakistan

Davis' continuing detention, his recent move to a prison from the police station, and the apparent impending murder charge could infuriate the United States. A senior U.S. official said that so long as Davis is detained, any major U.S.-Pakistan meeting would be dominated by a discussion about Davis -- making normal bilateral discussions right now difficult to impossible.

But the embassy in Islamabad rejected the claim made by Pakistani officials in an ABC news report that pressure to release Davis included a meeting between National Security Advisor Tom Donilon and Pakistan Ambassador to the United States Husain Haqqani in which Donilon threatened Haqqani with expulsion and the closure of U.S. consulates in Pakistan if Davis wasn't released last week.

"ABC News carried a story regarding a conversation in Washington between senior U.S. and Pakistani officials," said the statement, released by embassy spokeswoman Courtney Beale. "Although we are unable to discuss the substance of a private diplomatic meeting, U.S. Embassy Islamabad can state categorically that the description of the conversation in this report is simply inaccurate."

U.S. officials declined to specify which details in the story were inaccurate.

Haqqani also denied that he had been threatened.

"The characterization of my conversation with White House officials by ABC News borders fabrication," he said in a statement to ABC News today. "It is not our policy to reveal details of diplomatic conversations. I can say, however, that National Security Adviser Tom Donilon did, indeed, convey the US government's views about the case of Mr. Raymond Davis during a meeting on Monday evening but no ultimatum or threat was given. I conveyed the government of Pakistan's commitment to resolve the matter in accordance with Pakistani and international law. Both sides are working together to resolve the case expeditiously and to continue our multi-faceted strategic partnership."

Pakistani Officials: Shooting Victims Were Members of Pakistani Intelligence

Davis has become a political and intelligence football: he is caught between a federal government ruled by the Pakistan People's party and a Punjab government led by the opposition, which is more skeptical of U.S. policies; and he is caught in an intelligence game because he killed two men working for Pakistan's premiere intelligence agency, according to four Pakistani officials.

A congressional delegation from the House Armed Services committee visited Pakistan last weekend and raised the possibility that Davis' continuing detention would threaten military aid, according to a committee aide. But a senior Pakistani military official denied that was true.

"There were no threats," he said casually, shrugging his shoulders.

But there have been threats delivered to government officials, and the larger problem, those officials say, is that the pressure is boxing them in -- because it is eroding overall support for the United States.

Speaking in private drawing room conversations or in high-end coffee shops, even some of those who support the United States say they feel like they can't support Davis' release, especially not publicly. In their minds, the ambiguous nature of Davis' job, his killing two Pakistanis in broad daylight, and the wide coverage given to U.S. anger in Pakistan has shrunk the public acceptance of all U.S. policies in Pakistan.

"I think the response to the U.S. anger is more aggressive anti-American sentiments," said Ahmed Malik, sitting at the upscale Gloria Jean's coffee in Lahore. He and his friends said the U.S. was "bullying" Pakistan. "I think people feel it's totally unjustified for the Americans to ask for a man who's done something like this" to be released, Malik said.

Their increasing skepticism of U.S. diplomacy was echoed by the senior military official, who discussed Davis' detention on the condition of anonymity.

"It should disturb the U.S. when the liberal class, on the account of U.S. attitude and bullying… is showing a lot of frustration, anger, reservations," the official told ABC News.

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