Obama, Cameron pledge to help seek justice for Paris attacks

US President Barack Obama meets with British Prime Minister David Cameron (L) in the Oval Office of the White House in Washington January 16, 2015. [Photo/Agencies]

"When we have the ability to track that, in a way that is legal, conforms with due process, rule of law and oversight, then that's a capability we have to preserve," Obama said.

American Internet companies, concerned about keeping the trust of individual and commercial customers around the world, have sharply criticized government eavesdropping programs revealed by Snowden, the former NSA analyst. They have also publicly supported legislation aimed at restricting future surveillance.

In addition, Google, Facebook and other companies have expanded their own encryption programs to protect customers' communications in the wake of the Snowden revelations.

Beyond security issues, Obama and Cameron also discussed the state of the global economy. While US growth is on the rise and unemployment is falling, the White House is concerned that slowing growth in the European Union could have an impact here.

Cameron acknowledged those worries, saying the US and Britain "have to deal with the warning lights flashing in the global economy."