John Brennan, the counter-terrorism adviser nominated by President Obama to be the next head of the CIA, has reportedly agreed to exempt agency strikes in Pakistan from a new set of rules that attempts to justify and codify the use of drones to assassinate leaders of al-Qaida and other terrorist groups around the world, including US citizens.

The dispensation to allow so-called targeted killing to continue without restrictions in Pakistan removes from the new set of guidelines the most important and controversial target of drone strikes. In the past few weeks the frequency of US strikes in the tribal areas of northern Pakistan, where many al-Qaida and Taliban leaders are hiding out, has been stepped up.

The Washington Post reports that the CIA is close to finalizing the new guidelines on drone strikes, known as the "playbook". But a multi-agency committee of national security officials led by Brennan agreed to remove Pakistan from its terms.

The pass would allow the US to sustain heaving bombardments of the tribal regions via drones launched from bases in Afghanistan for another year or two, ahead of the withdrawal of most American forces from that country in 2014.

When Obama entered the White House in 2009 he made it his top foreign policy priority to put America back on the road of international law and to end the post-9/11 use of extra-judicial actions such as enhanced interrogations, extraordinary renditions and the detention of terror suspects at Guantanamo Bay. But to the dismay of civil liberties campaigners, over the past four years he has moved instead to institutionalize and set into US law many of these dubious practices.

The decision to give the US targeted-killing programme the appearance of legal propriety by codifying it, and now the temporary exemption granted from that codification to Pakistan, were both taken by Brennan. A counter-terrorism expert with 25 years experience in the CIA, his nomination to run the agency has raised eyebrows among civil liberties groups because of his senior role in the CIA under George W Bush at a time when torture was used on terror suspects and because of his fondness for drone strikes.

Targeted killing has been a particularly pronounced facet of US strategy in Pakistan. The UK-based Bureau of Investigative Journalism estimates that there have been 362 drone strikes in the country since 2004 – 310 of them launched on Obama's watch. The strikes have killed up to 3,461 people, 891 of them civilians.