U.S. Attorney General Jeff Sessions on Friday vowed a law enforcement war on opioids akin to the anti-drug efforts of the 1980s.

Speaking at Kennedy Airport before an audience of about 50 uniformed officers of the U.S. Customs and Border Protection force, Sessions said the painkilling narcotic “fentanyl is the No. 1 killer-drug in America. You know that.”

About 20,000 people died last year of fentanyl and synthetics, he said.

“I’m convinced this is a winnable war,” Sessions said. “We’ve done it before.”

Before the speech, Sessions toured a Kennedy Airport postal sorting facility to see how inspectors spot and intercept unlawful opioids, said Kelly Laco of the Justice Department’s press office. He was to fly out after the speech.

In remarks of about 20 minutes, Sessions touted new prescribing restrictions by the U.S. Food and Drug Administration, scrutiny of physicians who write prescriptions, prosecutions of those who unlawfully prescribe, and algorithms to identify “statistical outliers” and a renewed focus on the 800,000 pieces of mail that come through Kennedy Airport daily.

“Fraudsters lie but the numbers don’t lie,” Sessions said.

He said the nation ought to build a wall separating Mexico and the United States — a hallmark of President Donald Trump’s 2016 campaign pledge.

“A border wall is an important step to stopping the flow of drugs,” he said.

Sessions’ speech comes a day after Trump declared a public-health emergency, which expanded access to medical services but doesn’t open up any additional federal money to fight addiction.

Sessions said that Trump has a “passion” for combating drug addiction and deaths.

“We’re facing the deadliest drug crisis in American history,” Sessions said Friday. “Never seen anything like this.”

“He has a passion for this issue,” Sessions said.

Trump said he would launch publicity campaigns to encourage young people to avoid alcohol and drugs, waive rules to broaden access at treatment centers, and expand states’ ability to expand block grants.

Trump on Thursday did not declare a “national emergency,” as he promised in August, a declaration that would have allowed more federal dollars to flow.

Elsewhere in Washington on Thursday, Sessions suggested that the opioid epidemic was due to personal failings on the part of Americans who cannot “say no” to drugs. He said that marijuana might be a gateway drug to hard-core opioid addiction.

According to the federal Centers for Disease Control and Prevention, opioids were to blame for more than 33,000 deaths in 2015, the last year for which statistics were available.