The White House said the Republican leader will call for capital punishment for high-volume dealers "where appropriate under current law" during a speech in Manchester, New Hampshire -- a state hard hit by the opioid crisis.
An estimated 2.4 million Americans are addicted to opioids, a class of drugs that include prescription painkillers, as well as heroin. Trump`s move is designed to burnish his tough-on-crime credentials, and he pledged to fix the crisis when he took office a year ago.
But so far, he has struggled to make headway on an epidemic that kills an estimated 115 Americans a day due to overdoses, according to the government-funded National Institutes of Health.
Drug-related murder is already a capital offense in the United States, but no one has ever been executed using those rules. Officials indicated there would be no attempt to change the law to make the death penalty mandatory for trafficking alone, a move that would could well run afoul of Supreme Court rulings on proportional punishment.
In those rulings, the high court suggested that nothing other than murder can be considered a capital offense.With Republicans at risk of losing control of Congress in legislative elections in November, Trump is keen to rally his base ahead of the polls behind a tough-sounding message.
A series of special elections has seen Republicans struggle to match the intensity of anti-Trump sentiment, with high turnout among Democrats delivering a series of shock victories.
Most polls show Trump`s approval rating hovering around 40 percent, with supporters and opponents expressing intense feelings either way.
This announcement is likely to be no different in terms of how the public reacts.
Around 55 percent of Americans are in favor of the death penalty for murder, the lowest levels in decades.
Trump has previously mooted the "ultimate" punishment for drug dealers.
"Some countries have a very, very tough penalty - the ultimate penalty," he said in March. "And, by the way, they have much less of a drug problem than we do. So we`re going to have to be very strong on penalties."
Trump has praised Philippine President Rodrigo Duterte, whose war on drugs has led to the extra-judicial killings of alleged traffickers.
Philippines police say they have killed 4,100 drug suspects as part of the campaign, while rights groups claim the real toll is around three times the number. The International Criminal Court is investigating.
Experts say that the apparent link between low drug use and capital punishment in places like Singapore can be misleading.
Iran, they point out, also has the death penalty for drug use but still has one of the highest rates of opiate addiction in the world.
Many Democrats oppose the idea of executing drug dealers, and changing the law would require an act of Congress. "We will not incarcerate or execute our way out of the opioid epidemic," Democratic senator Ed Markey said last week.
"Extreme proposals like using the death penalty only perpetuate a harmful stigma associated with opioid use disorders and divert attention from meaningful conversations and progress on expanding access to treatment, recovery, and other public health initiatives," he said.
Trump is set to also announce measures to tackle "over-prescription, illicit drug supplies, and insufficient access to evidence-based treatment."