Donald Trump has said a “big day” is planned on national security, including an announcement to build a wall on the border between the US and Mexico.
The new Republican president is expected to sign several executive orders on immigration and border security this week.
They are likely to include the “extreme vetting” of people coming from seven predominantly Muslim countries in the Middle East and Africa.
This would restrict refugee access.
Mr Trump tweeted: “Big day planned on national security tomorrow. Among many other things, we will build the wall!”
Building a 2,000-mile wall along the Mexican border was one of his key proposals during the presidential election campaign.