In secret concessions to Pakistan, the US has tightened rules on drone strikes inside the country, apparently making them more selective as part of efforts to shore up its fragile relationship with Islamabad.
The Central Intelligence Agency has changed the rules on drone attacks, giving the State department greater sway in strike decisions and intimating Pakistan in advance about more operations, Wall Street Journal reported quoting officials.
The changes in the pattern of drone strikes -- which have killed hundreds of militants, including top commanders were undertaken after a high-level review that strongly backed the drone programme, but raised the bar on operations to minimise diplomatic blowback.
The concessions by the CIA, the paper said, came after military and diplomatic officials complained that large strikes were damaging the already fragile relations with Pakistan.
The change in engagement rules includes suspending strikes when Pakistani officials visiting the US.
"The bar has been raised. Inside CIA, there is recognition you need to be damn sure it's worth it," a senior official said, adding that the review had ultimately affirmed support for the CIA programme.
WSJ said that there was a measure of discord among administration officials on the interpretations of the outcome of the White House review.
"While some said that the CIA would weigh diplomacy more heavily in its activities, other said the impact was minimum and would remain as aggressive as ever," the paper said.
The US drone strikes in Pakistan are currently at their peak with the programme including 14 drone "orbits". Each "orbit" usually includes three drones, sufficient to provide constant surveillance over tribal area of Pakistan.
The CIA's fleet of drones includes Predators and larger Reapers. The drones carry Hellfire missiles and sometimes bigger bombs, can soar to altitude of 50,000 feet and reach cruise speed of upto 230 miles per hour.
The American drones over the past decades have become a key element of US national-security policy. The drone campaign has killed more than 1,500 suspected militants on Pakistani soil since President Barack Obama took office in 2009, US officials said.
The debate in Washington was fueled by a deadly drone strike on March 17 when missiles from the UAV killed more than 40 people, with infuriated Pakistani leaders claiming that most of them were civilians.
The March 17 attack was a "signature" attack, one of the two types used by the CIA which target groups of men believed to be militants or their sympathisers. The bulk of CIA strikes are signature strikes.
The second kind of drone strikes is called "personality" strikes which target known terrorist leaders. US officials say that under new rules of engagement, there may be screening of signature attacks but no changes in strikes targeting big terror commanders.
The officials also said that there will be no let up in intensified strikes in Pakistan focusing on the militant Haqqani network. The Pentagon, the State department as well as the White House have backed these strikes as serving US national interest.