- Video report by ITV News Washington Correspondent Robert Moore
Donald Trump has declared America's spiralling drug crisis a public health emergency.
The US president said the country's heroin and opioid addiction was the biggest drug crisis "in American history" - and possibly "in world history".
Mr Trump authorised a number of measures to help tackle the "scourge" of drug addiction, which contributed to 64,070 deaths in the US last year alone.
It is now the leading cause of death for Americans under the age of 50, and kills 175 people every day.
"This epidemic is a national health emergency," Mr Trump told a White House briefing on Thursday.
He said: "We can not allow this to continue. It is time to liberate our communities from this scourge of drug addiction.
"We can be the generation that ends the opioid epidemic."
The public health emergency declaration will last for 90 days but can be renewed.
It is not clear how much money the move will enable to be channeled into fighting the drug battle.
Mr Trump warned that drug addiction was a "world-wide problem" and lamented that it had been "so long in the making".
"Addressing it will require all of our efforts, and it will require us to confront the crisis in all of its very real complexity," he said.
The president continued: "Drug overdoses are now the leading cause of unintentional death in the US by far.
"More people are dying from drug overdoses today than from gun homicides and motor vehicles combined."
In a personal speech, Mr Trump also recounted the history of his brother Fred's battle with alcohol abuse.
The US leader criticised both Chinese and Mexican drug dealers for significantly contributing to the problem in the US.
Mr Trump used this point to reiterate his desire for a wall to be built across the border with Mexico, saying that 90% of heroin in American came from across the border.
"For too long we have allowed drugs to ravage American homes, cities and towns," he said.
"We owe it to our children and our country to do everything in our power to address this national shame and this human tragedy.
"We must stop the flow of all types of illegal drugs into our communities."
In a bold pledge, Mr Trump said that he wanted the next generation of Americans to know the "blessings of a drug-free life".
Mr Trump said "aggressive steps" would be taken to tackle the problem.
Federal agencies would be directed to do everything in their power to combat the crisis, he revealed.
A "massive advertising campaign" reaching out to young people to avoid prescription drugs would also be launched.
And the president also promised more research funding for opioid alternatives, saying that "lots of money" would be spent to come up with a non-addictive solution.