By Laura Jarrett

CNN

WASHINGTON (CNN) -- In his first major public speech since taking office, Attorney General Jeff Sessions pledged Tuesday that a Justice Department crackdown on violent crime will reverse what he views as a dangerous new trend.

Standing before a packed ballroom of the National Association of Attorneys General, Sessions harked back to his early time as a young prosecutor in Alabama and suggested that the nation "maybe got a bit overconfident" with more lax crime prevention efforts.

"We are in danger. ... We need to return to the ideas that got us here -- the ideas that reduce crime and stay on it," Sessions said. He expressed his concern that the spike in the murder rate is not an "aberration" or "one-time blip" but rather "the beginning of a trend."

President Donald Trump has repeatedly cited the rising murder rate as justification for a focus on law and order.

The US experienced its highest one-year increase in the murder rate in half a century between 2014 and 2015, but that is still down significantly from the early 1990s.

Following praise from Florida Attorney General Pam Bondi for vowing to crack down on illegal drugs, Sessions agreed that "crime does follow drugs."

"Drugs today are more powerful and more addictive," Sessions said. "I am dubious about marijuana -- I'm not sure we're going to be a better, healthier nation if we have marijuana being sold at every corner grocery store." He said he also plans to reduce the availability of illicit prescription drugs.

Separately, Sessions said he believes that a purported sea change in morale among those in law enforcement is on the way -- implying that the federal government should back off criticism of local law enforcement.

"Somehow, some way, we undermine the respect for our police -- oftentimes it makes their job more difficult -- it has not been well-received by them. We need to help police departments get better," Sessions said, and "I don't think it's mean to civil rights."

Immigration

A number of the state attorneys general and other top legal officials in the room -- including the attorney general of Virginia -- sued the Trump administration last month over his travel ban executive order. Sessions did not address the travel ban directly in his remarks Tuesday.

Sessions did, however, speak about immigration more generally -- largely echoing sentiments from his boss.

"There's nothing wrong with a lawful system of immigration," Sessions said, but "people who commit crimes are going to be out of here."

And he vowed to "confront" nations that refuse to take back individuals who have entered the US unlawfully and committed crimes.

As part of a question to Sessions, California Attorney General Xavier Becerra worried the Trump administration's immigration policies could have a chilling effect on community-based policing efforts because of fear some undocumented immigrants feel in reporting crimes to local police. Sessions began his remarks by citing the increase in crime nationwide while Becerra credited community-police relations in part with reducing crime in California over the past two decades.