U.S. President Donald Trump's order banning citizens of 12 countries from entering the United States goes into effect at 12:01 am ET (0401 GMT) on Monday, a move the president promulgated to protect the country from "foreign terrorists.

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.