President Donald Trump is to say that some drug dealers should be handed the death penalty, as part of a new plan to combat the US opioid crisis. Picture: AP Photo/Carolyn Kaster

Washington - President Donald Trump is to say that some drug dealers should be handed the death penalty, as part of a new plan to combat the US opioid crisis due to be presented on Monday.

A senior White House official told reporters Sunday that the Department of Justice would seek the penalty "when it's appropriate under current law" but gave no concrete examples.

However, Trump will ask the Senate and the House of Congress to lower the threshold amount of drugs sold that triggers mandatory minimum sentences for people who deal in particularly potent drugs.

Trump is to present the plan in New Hampshire, a state particularly affected by the opioid crisis, which has ravaged the United States in recent years.

Opioids including carfentanil and heroin killed 42 000 people in the country in 2016, and overdoses from such drugs are now the most common cause of death under the age of 50 in the country.

The new plan will also encompass efforts to reduce the amount of prescribed opioid-based painkillers by a third within three years and improve the care and treatment of addicts.

A nationwide campaign to educate people on the dangers of opioid abuse will also be launched.

Trump has repeatedly called for the death penalty for drug dealers, most recently at a rally this month in Pennsylvania, where he said some dealers "kill thousands of people during their lifetime."

He has also controversially praised Philippine President Rodrigo Duterte, who has launched a war on drugs in which thousands of people have been killed, as doing an "unbelievable job on the drug problem."