WASHINGTON – The Obama administration is debating whether to authorize a lethal strike against a U.S. citizen living in Pakistan who some believe is actively plotting terror attacks, according to current and former government officials.

It is the first time U.S. officials have actively discussed killing a U.S. citizen overseas since President Obama imposed new restrictions on drone operations in May.

The officials would not confirm the identity of the terror suspect, or provide any information about what evidence they have amassed about the suspect's involvement in attacks against Americans.

The first time the Obama administration carried out a targeted killing operation against a U.S. citizen was in September 2011, when a CIA drone killed the radical preacher Anwar al-Awlaki in Yemen, officials said little publicly about the operation. The White House acknowledged last year that four U.S. citizens had been killed in drone strikes during Obama's time in office. According to the White House, only al-Awlaki had been intentionally targeted.

During a speech in May, Obama said he intended to gradually shift drone operations from the CIA to the Pentagon, partly to make them more transparent. U.S. officials said then that drone strikes in Pakistan would continue to be launched by the CIA because Pakistan refuses to allow open U.S. military operations on its soil.

However, under a classified policy issued by Obama there is a strong preference for the Pentagon to carry out drone strikes against U.S. citizens, though the policy is said to allow exceptions if necessary.

U.S. officials said the new discussions about whether to strike the American in Pakistan had been going on since the middle of last year. The public got a glimpse of the debate last week when Rep. Mike Rogers of Michigan, the Republican chairman of the House Intelligence Committee, spoke angrily about the drone restrictions imposed by Obama.

"Individuals who would have been previously removed from the battlefield by U.S. counterterrorism operations for attacking or plotting to attack against U.S. interests remain free because of self-imposed red tape," Rogers said during a congressional hearing.

The new rules, Rogers said, are "endangering the lives of Americans at home and our military overseas in a way that is frustrating to our allies and frustrating to those of us who engage in the oversight of our classified activities."

Several senior officials in both the executive branch and Congress confirmed that even though the policy establishes a baseline rule that only the Pentagon is to conduct drone strikes against U.S. citizens, a clause makes an exception that would allow the administration to use the CIA.