Though White House, National Counterterrorism Center (NCTC) and Central Intelligence Agency (CIA) spokesmen have declined to comment on the database, officials have stated privately that kill lists will expand "for at least another decade", if not indefinitely. One official stated, "It’s a necessary part of what we do." Paul R. Pillar, the former deputy director of the CIA’s counterterrorism center, has stated, "We are looking at something that is potentially indefinite."