US hobbyists 'must register drones' from 21 December
Drones in the US, and the people who fly them, must be registered on a government database starting from 21 December.
Any drones purchased from that date onwards must be logged before the first outdoor flight, the country's Federal Aviation Administration (FAA) has said.
Existing drone owners have until 19 February 2016 to register their drones, but a $5 (£3.30) fee will be waived to encourage registration within the first 30 days.
FAA spokesman Les Dorr told the BBC that it would seek to educate, rather than punish, those found to have no registered their drones.
But he added: "For people who simply refuse to register, we do have enforcement tools available."
Those punishments could be civil penalties of up to $27,500, but in severe cases, criminal prosecutions could result in a $250,000 fine and a maximum of three years in prison.
The rule affects drones weighing in at half a pound to 55lb (228g to 22.7kg). Users older than 13 must register themselves, but parents can register on behalf of younger children.
Each drone will be given a unique identification number to be displayed on the device.
On Monday, the FAA promised the process would be "streamlined and user-friendly".
"Make no mistake: unmanned aircraft enthusiast are aviators and with that title comes a great deal of responsibility," US transportation secretary Anthony Foxx said in a statement.
"Registration gives us an opportunity to work with these users to operate their unmanned aircraft safely.
"I'm excited to welcome these new aviators into the culture of safety and responsibility that defines American innovation."
In depth: Drone discipline
Hobby drones. Unmanned aerial vehicles. Remote-controlled copters.
Call them what you will, they're becoming a nuisance.
A minority of irresponsible users has been flying them too close to aeroplanes and helicopters, wandering into restricted military airspace, spying on neighbours; disrupting sporting events and even injuring people.
It was only a matter of time before some trigger-happy vigilante shot one of the pesky privacy invaders out of the sky.
Regulators and law enforcers are struggling to cope with the growth in their popularity, increasing the likelihood that heavy-handed legislation could stifle innovation in a sector that has great commercial potential for businesses large and small.
Regulators had been under pressure to clamp down on what many people, particularly those in the emergency services, consider to be a growing menace - hobbyist drone users flying in unwanted places.
Firefighters in California said drones had disrupted efforts to contain wildfires.
However, some believe the drone database will be ineffective.
"The fact is that for the most part, when there are sightings, they don't actually get to recover the drone itself," Mickey Osterreicher, from the National Press Photographers' Association, told BBC News when consultations began in October.
"So, what would registering the drone accomplish?"
He added that further rules would not prevent bad drone use, drawing comparisons to people who drive cars without a licence or insurance, saying: "You really can't legislate against stupidity."
But other bodies, including the Association for Unmanned Vehicle Systems International (AUVSI), have backed the idea and taken an active role in consultations.
Follow Dave Lee on Twitter @DaveLeeBBC