"About a year ago, the president told his team to take a hard look at ways to have some sort of independent review of counter-terrorism operations, and that includes something like [the secret surveillance] court," said the official, who asked not to be identified discussing classified deliberations.
The team concluded that creating an outside court to authorize killings would pose political and constitutional hurdles and might prevent fast action against an imminent plot.
Other U.S. officials have said the administration is preparing a so-called playbook with rules and procedures for lethal strikes, and that they plan to shift some CIA drone missions to the military. That could increase transparency because the military does not conduct covert airstrikes.
At his confirmation hearing, Brennan said the administration had "wrestled with" the idea of a special court to help review or authorize lethal drone strikes, but he voiced skepticism.