 -- Attorney General Jeff Sessions is warning unauthorized immigrants in the United States of a new "Trump era" of stricter enforcement of the nation's immigration laws, unveiling harsher punishments for those living in the country illegally.

"For those that continue to seek improper and illegal entry into this country, be forewarned. This is a new era. This is the Trump era," Sessions said today in remarks to immigration officials in Arizona. "The lawlessness, the abdication of the duty to enforce our immigration laws and the catch-and-release practices of old are over."

He told agents from Customs and Border Protection that he promised to "bring the full weight of both the immigration courts and federal criminal enforcement to combat this attack on our national security and sovereignty."

The Department of Justice plans to add 125 immigration judges over the next two years via an expedited hiring process in an effort to combat the buildup of cases in the country's immigration courts. Sessions said that unauthorized immigrants will be charged with a felony instead of a misdemeanor if they try to enter the country illegally again.

"This is no accident," he said, citing a drop in unauthorized immigrants entering the country through the border with Mexico. "This is what happens when you have a president who understands the threat, who is not afraid to publicly identify the threat and stand up to it and who makes clear to law enforcement that the leadership of their country finally has their back."

Sessions said U.S. attorney's offices will have a border security coordinator for each district. He went on to emphasize that federal prosecutors will now be mandated to enforce existing laws barring the transportation and harboring of unauthorized immigrants and assaults on federal law enforcement officers.

President Donald Trump made combating unauthorized immigration a key part of his 2016 presidential campaign, vowing to build a wall along the U.S.-Mexico border.

ABC's Mike Levine contributed to this report.