Reuters has edited the story linked above [0] to state that the spokeswoman had improperly stated the effect and that, per a "senior administration official", permanent residents will be allowed to enter the United States after a "routine rescreening". [Permanent residents, or "green card holders", are non-citizens who have been granted a permanent right to reside in the United States.]
As expected, this is just another case of the media heavily misrepresenting an action by Trump because they want to destroy him at any cost.
[0] See http://archive.is/JViXa for a snapshot of the Reuters article at Sun Jan 29 01:52:21 EST 2017. The old snapshot is accessible by clicking the "history" link on that page, or going directly to http://archive.is/ZwEBt .