An aide to the national intelligence director says each U.S. intelligence agency is responsible for keeping Congress informed of its sensitive activities.

Robert Litt, general counsel for National Intelligence Director Dennis Blair, in a hearing by two subcommittees of the House intelligence panel, also said determining what constituted "significant intelligence activity" is driven by an individual agency's judgment, The Washington Post reported Wednesday.

"Generally speaking, each individual agency, or each individual component of the intelligence community, is responsible for its own notifications" to Congress, Litt said.

The hearing was part of a congressional inquiry about how well the nation's intelligence agencies follow the law requiring Congress be apprised of key operations. The inquiry was called after CIA Director Leon Panetta revealed that in 2001 the agency proposed forming assassination teams to target al-Qaida leaders but did not alert Congress, the Post said.

Responding to a question about why Congress would not to be informed, Litt said deciding what was a "significant intelligence activity" involves "the exercise of judgment," and "different people are going to have different judgments."

Litt said criteria for what is significant includes factors such as whether an operation could involve loss of life, its impact on foreign policy decisions and the risk of exposure, the Post said.

Although Blair encouraged the 16 intelligence agencies to compare their congressional notification procedures to standards established by his office, Litt said, the director has not required them to follow those guidelines.