HONOLULU, Hawaii - The Associated Press is reporting the U.S. is making plans to ban Americans from traveling to North Korea. 

The AP says the restriction would go into effect 30 days after a notice is published in the Federal Register, but it was not immediately clear when that would be.  

The move comes after the death of a Ohio university student Otto Warmbier, who passed away after falling into a coma into a North Korean prison.

Meanwhile, the Hawaii Emergency Management Agency is kicking off an educational campaign aimed at helping residents and visitors figure out what to do if the state is targeted in a nuclear missile attack from North Korea.

CBS Honolulu affiliate KGMB reports the agency said the threat to the islands from the rogue nation is "currently assessed to be low." 

But officials added ongoing North Korean missile tests —and growing public concern — have prompted them to work on preparedness and disaster management plans.

Vern Miyagi, administrator of the emergency management agency, stressed that the public shouldn't be alarmed by the planning.

Rather, he said, the public should see the preparation and education much like the work being done to prepare the public for hurricanes and tsunamis, which pose a greater risk to the state.

"We need to tell the public what the state is doing," Miyagi said. "We do not want to cause any undue stress for the public; however, we have a responsibility to plan for all hazards."

Earlier this month, North Korea tested an ICBM missile, drawing condemnation from the US and other countries. Experts say an ICBM like the one North Korea launched could reach Alaska and possibly even Hawaii.

The state plan considers what is currently a worst-case scenario: A 15-kiloton nuclear weapon detonated 1,000 feet above Honolulu.

In that scenario, public service announcements will tell residents, people should "get inside, stay inside, and stay tuned."

During the Cold War, the state said, Hawaii routinely updated plans and conducted drills related to nuclear attack scenarios. But those plans gathered dust as the threat faded.

Officials stressed, the time to plan is now — even if the threat level is low.

The Associated Press contributed to this report.