ISLAMABAD, PAKISTAN - Pakistan has demanded that the United States steeply reduce the number of CIA operatives and special operations forces working in the country and that it put on hold CIA drone strikes aimed at militants in northwest Pakistan. The request was a sign of the near collapse of cooperation between the two testy allies.

Pakistani and U.S. officials said in interviews that the demand that the United States scale back its presence was the immediate fallout from the arrest in Pakistan of Raymond Davis, a CIA security officer who killed two men in January during what he said was an attempted robbery.

In all, about 335 U.S. personnel -- CIA officers and contractors and special operations forces -- were being asked to leave the country, said a Pakistani official closely involved in the decision.

It was not clear how many CIA personnel that would leave behind; the total number in Pakistan has not been disclosed. But the cuts demanded by the Pakistanis amount to 25 to 40 percent of U.S. special operations forces in the country, the officials said. The number also included the removal of all the U.S. contractors used by the CIA in Pakistan.

The demands appeared severe enough to badly hamper U.S. efforts to combat militants who use Pakistan as a base to fight U.S. forces in Afghanistan and plot terrorist attacks abroad.

The reductions were personally demanded by the chief of the Pakistani army, Gen. Ashfaq Parvez Kayani, said Pakistani and U.S. officials, who requested anonymity while discussing the delicate issue.

Meetings in Washington

The scale of the Pakistani demands emerged as Lt. Gen. Ahmed Shuja Pasha, the head of Pakistan's chief spy agency, the Inter-Services Intelligence Directorate, arrived in Washington on Monday for nearly four hours of meetings with CIA Director Leon Panetta and Adm. Mike Mullen, the chairman of the Joint Chiefs of Staff.

Two senior U.S. officials said afterward that Pasha did not make any specific requests for reductions of CIA officers, contractors or U.S. military personnel in Pakistan at the meetings.

"There were no ultimatums, no demands to withdraw tens or hundreds of Americans from Pakistan," said one of the officials, who spoke on the condition of anonymity because of the tensions between the two spy services.

A CIA spokesman, George Little, called the meetings "productive" and said the relationship between the two services "remains on solid footing."

The meetings were part of an effort to repair the already tentative and distrustful relations between the spy agencies. Those ties plunged to a new low as a result of the Davis episode, which has further exposed the divergence in Pakistani and U.S. interests as the endgame in Afghanistan draws closer.

Both sides skeptical

The Pakistani army believes that Washington's real aim in Pakistan is to strip away its prized nuclear arsenal, said the Pakistani official closely involved in the decision on reducing the U.S. presence.

On the U.S. side, frustration has built over the Pakistani army's seeming inability to defeat a host of militant groups, including the Taliban and Al-Qaida, which have thrived in Pakistan's tribal areas despite more than $1 billion in U.S. assistance a year to the Pakistani military.

In a rare public rebuke, a White House report to Congress last week described the Pakistani efforts against the militants as disappointing.

In addition to the withdrawal of all CIA contractors, Pakistan is demanding the removal of CIA operatives involved in "unilateral" assignments like Davis' that the Pakistani intelligence agency did not know about, the Pakistani official said.

A U.S. official, who spoke on the condition of anonymity, said that the Pakistanis had asked "for more visibility into some things, and that request is being talked about."

Kayani has also told the Obama administration that its expanded drone campaign had gotten out of control, a Pakistani official said.