The House Intelligence Committee on Friday passed legislation that renews a controversial provision of the Foreign Intelligence Surveillance Act used to gather intelligence on foreigners abroad, with new language aimed at making it harder for the government to "unmask" Americans caught up in that surveillance.

That language is a Republican response to the unmasking of several Trump administration officials, which led many Republicans to worry that the Obama administration had politicized the program.

The FISA Amendments Reauthorization Act of 2017 was passed along party lines, as all Democrats voted against it. It would reauthorize the surveillance provision, Section 702, for four years.

The often-controversial FISA Section 702 is heavily relied on by U.S. intelligence officials and allows the National Security Agency’s surveillance program to collect digital communications with foreign suspects living abroad. Americans can be surveilled as part of that monitoring, and when they are, their identities are usually "masked."

But there are reasons and procedures for unmasking those Americans, and the GOP bill tightens the rules for doing so. First, it would require people asking for Americans to be unmasked to provide a justification for doing so, a rule that's currently in place but not always followed. It would also mandate reports to Congress on unmasking requests, and set up special procedures for unmasking members of any presidential transition team.

Democrats sought to amend that language in Friday's markup but failed.

The legislation was introduced by Chairman Rep. Devin Nunes, R-Calif., on Wednesday, as the Dec. 31 deadline to renew FISA Section 702 nears.