Two days after his advisers said otherwise, President Trump on Thursday said he does plan to formally declare the opioid addiction crisis an emergency — as the commission he appointed to study the epidemic had recommended.

"I'm saying officially right now it is an emergency," he told reporters at his golf course in Bedminster, N.J., where he has been vacationing. "We're going to spend a lot of time, a lot of effort, and a lot of money on the opioid crisis. We're going to draw it up and we're going to make it a national emergency."

Later Thursday, Trump released a statement telling his administration to "use all appropriate emergency and other authorities to respond to the crisis."

Gov. Christie, who chairs the opioid commission, said in a statement that he was grateful the president had accepted the recommendation.

"I am completely confident that the president will address this problem aggressively and do all he can to alleviate the suffering and loss of scores of families in every corner of our country," he said. "We look forward to continuing the commission's efforts and to working with this president."

Trump did not  mention the commission's other recommendations, which were outlined in a draft report released last week and focused entirely on public-health measures to curtail an epidemic that killed more than 900 people in Philadelphia last year and is on track to claim an additional 1,200 lives in the city by year's end. The commission wrote that 142 Americans a day die of drug overdoses.

"I'm glad that he declared a national emergency," said Philadelphia's public health commissioner, Thomas Farley, noting that the declaration was the first recommendation in the presidential commission's interim report. "Now I hope he follows through by following the rest of the recommendations."

At Community Behavioral Health, the city agency that handles Medicaid claims for substance-abuse treatment, deputy chief medical officer Rose Julius said the decision was "a wonderful call — a real opportunity to mobilize any and all resources that can be made available."

Experts have said that declaring a national emergency could free up federal funding and ease regulations so states can get more people into treatment, though some advocates have worried that the Trump administration will use the declaration to institute war-on-drugs-style policies that rely on heavy law enforcement to address the crisis. Speaking about solutions to the epidemic Tuesday, Trump did emphasize border protection and "strong law enforcement," though he also touched on working with health-care providers and preventing drug use.

"It remains to be seen how this will change the course of the epidemic," Caleb Alexander, codirector of the Johns Hopkins Center for Drug Safety and Effectiveness, said in an email. "There is no question that freeing up funding from the Federal Disaster Relief Fund to get people into treatment will help reduce injuries and deaths from opioids, but the declaration may also be used as a means to increase sentencing and other penalties that hurt people with opioid addiction – we aren't going to arrest our way out of this epidemic."

And he said he found the administration's promises to combat the opioid epidemic ironic given its support for efforts to repeal the Affordable Care Act, which had proposed cuts to Medicaid: "The administration has spent its first six months in office doing everything possible to take health-care coverage away from more than 20 million Americans, when what people with opioid addiction urgently need most is health care."

On Tuesday, Health and Human Services Secretary Thomas Price said the president would not be declaring an emergency because the funding needed to fight the crisis could be deployed without an official declaration. Trump didn't say why the administration had reversed course.

Julius said the opioid commission's report — which recommended removing certain Medicaid restrictions, improving access to naloxone, an overdose-reversing drug, and expanding access to medication assisted treatment — should guide the president's agenda on the crisis.

Price has criticized medication-assisted treatments like methadone and suboxone as simply "substituting one opioid for another."  But while both medications are opioids, a body of scientific research has found that they significantly increase the odds of successful treatment and reduce overdose fatalities.

They are "the gold standards," said David T. Jones, commissioner of the Philadelphia Department of Behavioral Health and Intellectual disAbility Services. He added that he hoped Trump's action would lead to uniform policies from the federal government.

Jose Benitez, the executive director at Prevention Point, the needle-exchange and advocacy group that serves people suffering from addiction in Kensington, said Thursday that he hoped the declaration would bring federal resources and wider attention to the crisis.

He had spent much of the week at the former encampment along the railroad tracks near Gurney Street, where the city has been running cleanup efforts and outreach for the hundreds of people who lived and used heroin there.

"This is a public-health crisis and we have to treat it as such," Benitez said. "Drug use is a disease, and so it needs that kind of treatment. It needs a clinical approach."

In a statement, the National League of Cities said the epidemic has "long warranted the status of a national health emergency" and said it welcomed the federal government's involvement.

"True progress will only come if federal, state and local governments work together on solutions," the statement read.