Attorney General Jeff Sessions has ordered a "zero tolerance" policy aimed at people entering the United States illegally for the first time on the Mexican border.

His directive Friday tells federal prosecutors in border states to put more emphasis on charging people with illegal entry, which has historically been treated as a misdemeanor offense for those with few or no previous encounters with border authorities. Smugglers and repeat offenders are usually charged with more serious crimes.

Sessions tells prosecutors to ask for additional resources if needed to prosecute cases. As a model, he points to a Border Patrol effort launched in 2005 that typically resulted in a conviction and short time in jail.

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Earlier this week, Sessions established quotas for immigration judges to reduce court backlogs.

Sessions' move is a part of the Trump administration's tough stance on illegal immigration. Earlier this week, the president announced he is sending the National Guard to protect the southern border.

Mr. Trump devoted most of his remarks that were supposed to focus on tax reform Thursday on illegal immigration and crime instead.

"We cannot let people enter our country. We have no idea who they are, what they do, where they came from," Mr. Trump said. "We don't know if they are murderers, if they're killers, if they're MS-13."

He also lashed out about the caravan of immigrants coming through Mexico, which seemingly factored into his decision to sign a proclamation sending the National Guard to protect the southern border. He even brought up his controversial comments from his 2015 presidential campaign launch, when he called some Mexican immigrants "rapist." On Thursday, Mr. Trump, without citing any statistics, said women are being "raped" like never before.

"Remember my opening remarks at Trump Tower, when I opened," Mr. Trump said. "Everybody said 'oh, he was so tough.' And I used the word rape. And yesterday, it came out where this journey coming up — women are raped at levels that nobody's ever seen before. They don't want to mention that. So, we have to change our laws."