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!”
Meanwhile, the Dow Jones traded above 20,000 for the first time, as traders bet that Mr Trump’s policies will boost the economy.
Building a 2,000-mile wall along the Mexican border was one of his key proposals during the presidential election campaign.
Mr Trump said Mexico would pay for the wall, which he estimated would cost about $8bn (£6.4bn).
He has since said the US would recoup the costs from its neighbour at a later date.
But Mexico’s president and senior officials have said that they will not pay for the wall, despite Mr Trump’s campaign pledge.
There could also be measures that force so-called sanctuary cities in the US to co-operate with the authorities on deporting illegal immigrants.
“Sanctuary cities” are places that don’t arrest or detain immigrants living in the country illegally.
Meanwhile, a draft White House order raises the possibility that overseas “black site” CIA-run prisons could be reopened.
The document asks senior national security officials whether the president should “reinitiate a program of interrogation of high-value alien terrorists to be operated outside the United States”.
The order, obtained by the Associated Press, explicitly rejects “torture”.
Later this week, Mr Trump is expected to announce immigration restrictions from seven African and Middle Eastern countries, including Syria, Yemen, and Iraq.
He is also likely to halt access to the country for some refugees – until the vetting process can be made more rigorous.