The Senate Intelligence Committee appears to be moving toward swift passage of a bill that would “change but preserve” the once-secret National Security Agency program that is keeping logs of every American’s phone calls, Senator Dianne Feinstein, the California Democrat who leads the panel, said Thursday.
Ms. Feinstein, speaking at a rare public hearing of the committee, said she and the top Republican on the panel, Senator Saxby Chambliss of Georgia, are drafting a bill that would be marked up — meaning that lawmakers could propose amendments to it before voting it out of committee — as early as next week.
After the existence of the program became public by leaks from the former N.S.A. contractor Edward J. Snowden, critics called for it to be dismantled. Ms. Feinstein said her bill would be aimed at increasing public confidence in the program, which she said she believed was lawful.
The measure would require public reports of how often the N.S.A. had used the calling log database, she said. It would also reduce the number of years — currently five — that the domestic calling log data is kept before it is deleted. It would also require the N.S.A. to send lists of the phone numbers it searches, and its rationale for doing so, to the Foreign Intelligence Surveillance Court for review.
By contrast, a rival bill drafted by skeptics of government surveillance, including two members of the committee, Senators Ron Wyden of Oregon and Mark Udall of Colorado, would ban the mass call log collection program.
That more extensive step is unlikely to pass the committee. Ms. Feinstein contended that “a majority of the committee” believed that the call log program was “necessary for our nation’s security.”
Ms. Feinstein said her bill with Mr. Chambliss would also require Senate confirmation of the N.S.A.’s director. At the same time, it would expand the N.S.A.’s powers to wiretap without warrants in the United States in one respect: when it is eavesdropping on a foreigner’s cellphone, and that person travels to the United States, the N.S.A. would be allowed to keep wiretapping for up to a week while it seeks court permission.
That step would remove the largest number of incidents in which the N.S.A. has deemed itself to have broken rules about surveillance in the United States. Those incidents were identified in a May 2012 audit leaked by Mr. Snowden.
The rival proposals pushed by Mr. Wyden and Mr. Udall would also ban the N.S.A. from warrantless searches of Americans’ information in the vast databases of communications it collects by targeting noncitizens abroad. And it would prohibit, when terrorism is not suspected, systematic searches of the contents of Americans’ international e-mails and text messages that are “about” a target rather than to or from that person.
Still, most of the senators on the Intelligence Committee, which had received briefings about the call log program and other surveillance even before Mr. Snowden’s leaks, used the hearing on Thursday to largely defend the programs and criticize the disclosures.
Mr. Chambliss suggested that people could die because of Mr. Snowden’s disclosures, and he pressed Gen. Keith Alexander, the N.S.A. director, to describe the program’s value.
“In my opinion,” General Alexander said, “if we had had that prior to 9/11, we would have known about the plot.”
Officials have struggled to identify terrorist attacks that would have been prevented by the call log program, which has existed in its current form since 2006. The clearest breakthrough attributed to the program was a case involving several San Diego men who were prosecuted for donating several thousand dollars to a terrorist group in Somalia.
Mr. Wyden pressed General Alexander about whether the N.S.A. had ever collected, or made plans to collect, bulk records about Americans’ locations based on cellphone tower data.
General Alexander replied that the N.S.A. is not doing so as part of the call log program, but that information pertinent to Mr. Wyden’s question was classified.