By Steve Holland and Patricia Zengerle
WASHINGTON (Reuters) - The White House moved on Monday to reassure U.S. allies and Americans concerned about the sweeping nature of the National Security Agency's surveillance practices by acknowledging that more constraints are needed to ensure that privacy rights are protected.
Amid a growing uproar in Europe and a protest by a key U.S. senator, officials said they would review intelligence collection programs with an eye to narrowing their scope.
"We need to make sure that we're collecting intelligence in a way that advances our security needs and that we don't just do it because we can," said White House spokesman Jay Carney.
President Barack Obama has come under fierce criticism abroad over allegations that the NSA tapped the mobile phone of German Chancellor Angela Merkel and conducted widespread electronic snooping in France, Italy, Spain and elsewhere.
The accusations have caused tensions between the United States and some of its closest traditional allies and could imperil a U.S.-European trade deal and trans-Atlantic information sharing.
Senator Dianne Feinstein, a California Democrat who chairs the Senate Intelligence Committee, said the White House had told her "that collection on our allies will not continue, which I support."
At least some of the spying appeared to have been done without Obama's knowledge.
"It is my understanding that President Obama was not aware Chancellor Merkel's communications were being collected since 2002," Feinstein said in a statement.
"That is a big problem," she said, adding that oversight of the NSA "needs to be strengthened and increased."
Feinstein pledged that her committee will conduct a major review into all intelligence collection programs.
Caitlin Hayden, spokeswoman for the White House National Security Council, said a White House review Obama ordered last summer has a special emphasis on examining whether the United States has the "appropriate posture when it comes to heads of state," and is looking at how to coordinate with U.S. allies and what constraints might be appropriate.
The snooping scandal is a direct result of disclosures of U.S. secrets made to media organizations by Edward Snowden, a former NSA contractor now living in asylum in Russia.
Carney told reporters that with new intelligence-gathering capabilities "we recognize there needs to be additional constraints on how we gather and use intelligence." This could include greater oversight and transparency, he said.
The comment suggested changes were in the offing on the scale of the electronic spying as part of the White House review of the collection activities of the NSA and other intelligence agencies. The review is to be completed by year's end.
In an interview with ABC's Fusion network, Obama acknowledged that national security operations are being reassessed to make sure the NSA's growing technical spying capability is kept under control.
"We give them policy direction," Obama said. "But what we've seen over the last several years is their capacities continue to develop and expand, and that's why I'm initiating now a review to make sure that what they're able to do, doesn't necessarily mean what they should be doing."
There was no sign that the director of the National Security Agency, General Keith Alexander, could be forced out over the controversy, with the White House underscoring that Obama retains full confidence in him and other NSA officials.
Alexander and his deputy, Chris Inglis, are due to retire early next year, moves unrelated to the Snowden controversies. Both men, along with Director of National Intelligence James Clapper and Deputy Attorney General James Cole are due to testify before a House of Representatives committee on Tuesday.
"CONFIDENCE IS VANISHED"
A European delegation took the concerns about the issue to Capitol Hill, where members of the European Parliament met U.S. lawmakers and spoke of the need to rebuild trust.
"Confidence is vanished," said Elmar Brok, a German member of the European Parliament. "We have to work hard that confidence is re-established between the leaders, between our people."
After Obama and Merkel spoke by phone last week, the White House said the United States is not currently tapping her phone and will not in the future, begging the question of whether it had been done in the past.
Feinstein's statement appeared to confirm the monitoring at least of Merkel.
"With respect to NSA collection of intelligence on leaders of U.S. allies - including France, Spain, Mexico and Germany - let me state unequivocally: I am totally opposed," she said.
The Wall Street Journal reported that the NSA ended the program that involved Merkel after the operation was uncovered in the White House review that began in the summer. The program also involved as many as 35 other world leaders, some of whom were still being monitored, the report said.
The United States and many lawmakers have defended the NSA programs as crucial to protecting national security and helping thwart militant plots. They have insisted that programs involving U.S. citizens are carefully overseen by Congress and the legal system.
Still, the Obama administration is well into a review of its intelligence-gathering procedures. Hayden said "we have already made some decisions through this process and expect to make more as we continue."
After the closed-door talks between U.S. lawmakers and the European Parliament delegation, U.S. Representative Mike Rogers, a Republican who chairs the House Intelligence Committee, said they discussed the need to rebuild trust, the need for cooperation and the need to share intelligence.
"It started to identify some of the differences that we have that we're going to have to bridge. That's a good thing. That's a good start and that's why we've pledged to take a delegation back to Brussels to follow up on this conversation," he said.
Rogers, a staunch defender of U.S. intelligence agencies, said there are misperceptions about what they have been doing, although he acknowledged the EU parliamentarians have legitimate concerns.
"It's important to understand that we're going to have to have a policy discussion that is bigger than any individual intelligence agency of either Europe or the United States," he said.
(Additional reporting by Roberta Rampton and Mark Felsenthal; Editing by Warren Strobel, Jim Loney and Christopher Wilson)