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.

Of the 12 countries from which travel is fully restricted, three are embroiled in bloody civil wars. Many of the other countries are also undergoing conflicts.