Joint U.S.-Pakistan intelligence operations have been halted since late January, reflecting strain in a relationship seen as crucial to combating militants and the war in Afghanistan.
Uneasy U.S.-Pakistani ties have become even more tense after a string of diplomatic disputes so far this year, including a massive drone strike in March and the case of Raymond Davis, a CIA contractor who shot dead two Pakistanis on January 27 in the eastern city of Lahore.
U.S. official familiar with the state of relations said the Pakistanis are making more effort to curb, restrict, or at least more intensely monitor, CIA activities. The revelation that armed CIA contractors such as Davis were working in Pakistan deeply angered and embarrassed the ISI.
Since then, a few dozen contractors the ISI says are associated with the agency -- the exact number is unclear -- and part of a parallel intelligence network have quickly and quietly left the country.
A small contingent of American troops training Pakistanis in counter-insurgency is also in danger of being reduced.
pakistan Army's continued support to Islamic terrorists like the Taliban is widely attributed to the unusually high death of American & NATO troops stationed in Afghnistan to defeat these very entities.
The frequency of drone strikes, an unacknowledged CIA program that the United States considers its most successful weapon against al Qaeda and the Taliban leadership and which relies on least Pakistani cooperation, also has fallen, with just nine strikes in March compared to a peak of 22 in September 2010.
A semi-annual White House report on Afghanistan and Pakistan harshly criticized Pakistan as having "no clear path toward defeating the insurgency."
The strain in relations could hinder efforts by the Obama administration to get the annual $1.5 billion in economic assistance for Pakistan appropriated for the 2012 fiscal year through Congress.