President Trump signed a proclamation to ban travel from certain countries, citing national security risks. It's set to take effect at 12:01 a.m. Monday.

Here is a closer look at why the administration says it is instituting full bans on foreign nationals traveling to the U.S. from 12 nations.

President Trump on Wednesday signed a travel ban on 12 countries, primarily in Africa and the Middle East, reviving an effort from his first term to prevent large numbers of immigrants and visitors from entering the United States.