GUATEMALA CITY (Reuters) - U.S. Homeland Security Secretary John Kelly said on Wednesday that President Donald Trump's executive order on immigration was aimed at catching undocumented immigrants and returning them to their countries of origin.

The order "emphasized the mission of intercepting irregular immigrants from many countries on our borders, treat them humanely and return them to their countries of origin as fast as possible," he said in a news conference in Guatemala.

Kelly's comments come the day after the United States issued new guidelines that included a plan to deport undocumented immigrants to the country they arrived from, which in many cases means Mexico.

(Reporting by Sofia Menchu)