The National Security Agency director and other intelligence officials have been making the case within the Obama administration that the NSA should play a bigger role in protecting computer networks in the U.S., according to current and former U.S. officials.

The proposals from Army Gen. Keith Alexander and others would expand the NSA's authority to allow it to block or pre-empt cyberattacks targeting entities within the U.S. and to scan for cyberthreats but not monitor the content of communications, these officials said....