Last week, President Donald Trump said he would finally declare the opioid crisis a national emergency — more than two months after he first promised an emergency health declaration for the most deadly drug overdose crisis in U.S. history.

"It's a very important step," Mr. Trump said of the emergency declaration last Monday in the White House Rose Garden. "And to get to that step, a lot of work has to be done, and it's time-consuming work." Still, he told reporters, "We are going to be doing that next week."

What that "time-consuming work" is, exactly, the Trump administration has not said. And White House Press Secretary Sarah Huckabee Sanders did not entirely seem to embrace the president's timetable.

"There's a very in-depth legal process that goes with declaring a national emergency. We'll make further announcements on that next week, but there have been multiple people -- it's an interagency process," Sanders said.

But one concern may be that it's hard to figure exactly how a national emergency declaration would apply. Lainie Rutkow of Johns Hopkins Bloomberg School of Public Health told Vox, "No one can point you to the exact model for how this would work for an emergency that's been declared for a noncommunicable health condition. This is a new thing."

Not everyone in the Trump administration agreed that declaring opioids a national emergency was the right approach. Only two days before Mr. Trump's initial announcement in August, then-Health and Human Services (HHS) Secretary Price dismissed the idea of an emergency declaration — a recommendation first made by the White House Commission on Combating Drug Addiction and the Opioid Crisis.

"The resources that we need or the focus that we need to bring to bear to the opioid crises can be addressed without the declaration of an emergency," he said at the time.

Obama HHS Secretary Kathleen Sebelius takes a different view, telling CBS News that she was surprised that the national emergency was not formally declared right when Trump took office. But she pointed out that the administration could also be struggling with figuring out whether it's looking at a public health problem or a law enforcement problem.

"Will people have access to treatment or not?" Sebelius said over the phone on Friday. "Will we treat this like a public health crisis instead of as an incarceration issue? If you declare a public health crisis then you have to treat it like a public health crisis. There doesn't seem to be any shared agreement within the administration."

The Trump administration is also scrambling to fill top posts that would typically be involved in the coordinating the response to the opioid crisis — on top of large existing staffing gaps.

Just this week, Rep. Tom Marino withdrew his nomination from leading the Office of National Drug Control Policy after a "60 Minutes"/Washington Post report singled him out for his role in passing a law that significantly curbed the DEA's efforts to crack down on the opioid epidemic.