Trump's travel ban is set to begin Monday. Here's what to know.

Washington — President Trump signed a proclamation late Wednesday barring travelers and immigrants from a dozen countries and restricting the entry of nationals from seven other nations.

With the move, the White House cited concerns about national security. The president said the recent attack at a march supporting Israeli hostages in Boulder, Colorado, had "underscored the extreme dangers posed to our country by the entry of foreign nationals who are not properly vetted, as well as those who come here as temporary visitors and overstay their visas."

"We don't want them," Mr. Trump said.