Media playback is unsupported on your device Media caption "I learned because of Fred," Trump said of his brother, who was addicted to alcohol

US President Donald Trump has called America's painkiller-addiction crisis a "national shame" as he declared it a public health emergency.

Mr Trump announced a plan to target the abuse of opioids, which kill more than 140 Americans each day.

The president has previously promised to declare a national emergency, which would have triggered federal funding to help states combat the drug scourge.

The move instead redirects grant money to be used in dealing with the crisis.

Mr Trump said on Thursday at the White House: "More people are dying from drug overdoses today than from gun homicides and motor vehicles combined.

"These overdoses are driven by a massive increase in addiction to prescription painkillers, heroin and other opioids."

He added: "The United States is by far the largest consumer of these drugs using more opioid pills per person than any other country by far in the world."

Mr Trump signed a presidential memorandum directing his acting health secretary to declare a nationwide public health emergency and ordering all federal agencies to take measures to reduce the number of opioid deaths, according to senior White House officials.

The order will also ease some regulations to allow states more latitude in how they use federal funds to tackle the problem.

But the White House plans to fund the effort through the Public Health Emergency Fund, which reportedly only contains $57,000 (£43,000).

The Trump administration will then work with Congress to approve additional funding in a year-end spending package, senior officials said.

Other elements of the directive include:

Allow patients further access to "telemedicine" so they can receive prescriptions without seeing a doctor

Make grants available to those who have had trouble finding work due to addiction

The Department of Health and Human Services will hire more people to address the crisis, particularly in rural areas

Allows states to shift federal funds from HIV treatments to opioids, since the two are linked as drug users often share infected needles

Proponents suggest Mr Trump's announcement is a critical step in raising awareness about the nationwide epidemic, while some critics argue the move does not go far enough.

"The lack of resources is concerning to us since the opioid epidemic presenting lots of challenges for states' budgets," Michael Fraser, executive director of the Association of State and Territorial Health Officials, told Politico.

"My hope is people will realise with no new money the ball is going to be in Congress's court," he added.

Senator Bernie Sanders later tweeted that while Mr Trump was "right that the opioid crisis is a national emergency", Friday's announcement was "nothing more than an empty promise".

"Millions depend on Medicaid [healthcare funding] for opioid treatment. Trump's solution is to cut Medicaid by $1 trillion. That is a disgrace," wrote the Vermont senator.

Taking the first step

Rajini Vaidyanathan, BBC News, Washington

Addiction to painkillers and heroin has blighted so many communities across the US - both urban and rural.

As I travelled the country reporting on last year's election, I remember the hairdresser in Arkansas whose ex-husband died from medicines he'd been given for his bad back, the family in New Hampshire who'd lost a teenage daughter to an overdose and heard stories of doctors who'd become hooked on the very pills they'd prescribed.

President Trump has stopped short of declaring this crisis a national emergency, despite earlier indications he would.

Instead his public health emergency is more of a short-term measure which doesn't allocate as much funding. Recovering addicts and charities I've talked to say more investment in round-the-clock rehab and treatment is what is needed to make a difference.

But while today's announcement is welcome, many will now be looking to Congress to take more action and secure more money to deal with this crisis.

Since 1999, the number of deaths involving opioids have quadrupled, reaching 33,000 deaths in 2015, according to the Presidential Commission on Combating Drug Addiction and the Opioid Crisis, citing data from the US Centers for Disease Control and Prevention (CDC).

The CDC first declared opioids, a class of pain medications as well as some street drugs, to be an "epidemic" in 2011.

Mr Trump first announced his intention to declare opioid abuse a "national emergency" in August.

"The opioid crisis is an emergency, and I'm saying officially right now: It is an emergency. It's a national emergency," he said at the time.

Media playback is unsupported on your device Media caption "We're going to spend a lot of time, a lot of effort and a lot of money on the opioid crisis"

Experts had urged Mr Trump to use his presidential power under the Stafford Act to declare a national emergency, which would have given states access to money from the federal Disaster Relief Fund.

States would have had immediate access to funding, much like they would after a natural disaster.

But senior officials told reporters that declaring that sort of emergency was not a good fit for an ongoing crisis.

The announcement comes after Mr Trump's pick for drug czar withdrew his nomination following a report that he helped neuter government attempts to tackle the opioid crisis.

Pennsylvania congressman Tom Marino pushed a bill that reportedly stripped a federal agency of the ability to freeze suspicious painkiller shipments.

Health Secretary Tom Price also resigned last month after it was revealed he was using expensive private planes for official business.

As a candidate, Mr Trump frequently pledged to tackle the drug crisis, and often campaigned in the hardest-hit states.

More on the US opioid crisis

Media playback is unsupported on your device Media caption America's new generation of addicts