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.

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.

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.