Mohammad Sharafoddin, his wife and young son managed to make it out of Afghanistan as refugees nine years ago, at one point walking 36 hours in a row over mountain passes.

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.

When Trump included Haiti in a list of countries on which he was imposing a near-total travel ban, some saw a culmination of a long campaign against the population.