Iraq - which was covered in the previous seven-nation order - has been removed from the new one after agreeing to additional visa vetting measures.
The directive, which includes a 120-day ban on all refugees, takes effect on 16 March.
The new order was unveiled by Secretary of State Rex Tillerson, Attorney General Jeff Sessions and Department of Homeland Security Secretary John Kelly.
"The fact remains that we are not immune to terrorist threats and that our enemies often use our own freedoms and generosity against us," said Mr Kelly.