AUGUSTA — State officials lauded the biggest drop in Maine’s crime rate in two decades at a news conference Tuesday, but illegal drugs continue to cause serious law enforcement problems in the state.

While Public Safety Commissioner John Morris called the drop in the crime rate “good news,” Gov. Paul LePage said the decrease — 9.1 percent from 2012, the most substantial single-year decrease in 20 years — could have been greater if the Legistlature had passed his proposal to hire more law enforcement agents and after the press conference challenged the Legistlature to return to pass his bill.

At Tuesday’s news conference at the Augusta Police Department, which was also attended by Augusta Deputy Chief Jared Mills, Morris told those gathered it was “great to have good news for a change.”

Except for aggravated assaults, the statistics released Tuesday by the state Department of Public Safety showed an across-the-board decline.

“Maine continues to be one of the safest states in the country and last year was the safest in Maine in two decades,” Morris said in a prepared statement released before the press conference. “The crime decrease is great news for the short term, and we will continue our efforts on the law enforcement side.”

Violent crime in Maine, which includes rape, murder and aggravated assault, remained at 1 incident per 1,000 people, four times lower than the national average.

But the continued role of illegal drugs in the state — much of it coming in from out of state — “continues to be the core issues that drives Maine crime,” Morris said.

Through the first five months of 2014, drug offenses have increased significantly, said Morris.

Morris said drug distributors are operating in nearly every county selling crack, heroin and oxycodone. “Make no mistake. They are organized and ruthless. They are entrepreneurs who are here to make money no matter how.”

The most dramatic declines announced Tuesday were in the number of arsons, which dropped from 226 in 2012 to 140 in 2013, a drop of 38 percent.

Robberies dropped 20 percent, from 421 reported cases in 2012, to 335 reported in 2013.

The overall crime rate of 24.3 offenses per 1,000 people remains lower than the national average for 2012, when 30.8 crimes per 1,000 in population were reported.

Aggravated assaults was the only category in which there was an increase, jumping from 803 reported in 2012 to 943 recorded cases last year, a 17.4 percent increase, according to the state.

Statewide, nine fewer rapes were reported to police, a decline of 2.4 percent. In rural areas, that figure was even larger, with 18 fewer reported rapes.

However, the Maine Coalition Against Sexual Assault cautioned that the decline represents what’s reported to law enforcement.

“Approximately 13,000 Mainers experience sexual violence each year, but in 2013, only 359 rapes and attempted rapes were reported,” said Cara Courchesne, a spokeswoman for the group. “Clearly, that’s a huge gap.”

LePage, who joined Morris at the press announcement, repeated his criticism of the Democrat-controlled Legislature for failing to pass his $3.2 million proposal to hire more drug enforcement agents, assistant district attorneys and judges, a measure designed to combat opioid use, including, heroin, that has swept Maine in the last decade.

Morris told the press Tuesday that LePage was there “because he wants to thank all those people in law enforcement, in courts, prosecutors, domestic violence coalitions, sexual assault coalitions. Everybody has worked together to develop this result.”

But LePage told those gathered that those people weren’t enough — he wanted to add 14 drug enforcement agents, four assistant attorneys general assigned to drug prosecutions and four judges to staff drug courts.

“We have good news, but quite frankly, it’s not good enough,” LePage said. “We need those judges, we need those DAs and we need those agents on the street. I’m not so concerned right now with those that are addicted.”

LePage’s comments came on the same day that the governors of the five other New England states met for a “drug summit” at Brandeis University in Waltham, Mass.

LePage was invited, but did not attend because of a scheduling conflict, said Adrienne Bennett, the governor’s spokeswoman.

LePage urged lawmakers to return in a statement his office released after Tuesday’s press conference.

“I could call the Legislature back to take up my bill, but Democratic leaders could simply recess immediately and go home,” LePage said at the news conference. “I cannot force them to do something they are not willing to do.”

LePage also said that too much money is being spent on treating those with drug problems and not enough is spent on enforcing drug crimes. “I’m not so concerned right now with those that are addicted,” he said.

Democratic legislators in the House approved a modified version, adding $750,000 for drug treatment to the bill and scaling back the law enforcement component to 10 Maine Drug Enforcement Agency agents, two assistant attorneys general and two judges, with a reduced overall price tag of $2.5 million.

Legislators called the modified bill a compromise that aligns with similar legislation passed in other states, with come critics saying noting that LePage’s proposal reflected a “war on drugs” approach that has been ineffective in reducing addiction and criminal activity.

The governor vowed to veto any version with lower staffing levels, but he never got the opportunity, as the modified bill died in the Senate when legislators went home at the end of the session in May.

More than hiring additional enforcement, LePage also suggested Tuesday that it would “send a message” if Maine passed tougher mandatory minimum sentencing laws for drug offenders, similar to a recent law in Louisiana that elevated the minimum penalty for selling heroin from five years in prison to 10 years, and extended the maximum for the same crime from 50 years in prison to 99 years.

“I think it’s time,” LePage said. “If we’re going to fill our prisons with somebody, let’s fill it with the people who are poisoning our kids and get them off the streets. Make sure they never have an opportunity to do it again.”