The Federal Aviation Administration has ordered all U.S.-registered Boeing 787 passenger jets to stop flying until the risk of possible fires caused by lithium batteries aboard the craft can be evaluated.

The FAA said it will work with Boeing and United Airlines – the only American carrier that currently operates 787s – to get the wide-bodied, twin-engine jets back in service as quickly and safely as possible.

The government's aviation watchdog said in a statement that all 787 operators must demonstrate to the FAA that planes' lithium batteries are safe before flights can resume.

Hours earlier, Japan's two biggest airlines, All Nippon Airways and Japan Airlines, grounded all their Dreamliners – 24 aircraft – after one of the new jets made an emergency landing in Japan, after a cockpit warning light signaled a battery problem and passengers reported a burning smell in the cabin. No serious injuries were reported as passengers and crew scrambled down escape chutes after the jet touched down.

Even before Wednesday's developments, recent problems with the 787 had prompted U.S. regulators to launch a safety review of the aircraft. A battery problem was believed to be the cause of a small fire that broke out aboard an empty 787 as it was being serviced on the ground in Boston; other incidents have involved leaking fuel, a cracked windshield and brake problems.

Boeing had no immediate comment on the FAA action, but the company's stock price fell 2 percent in trading after U.S. markets formally closed.

U.S.-based Boeing has sold or has commitments to build more than 800 of the planes for airlines around the world. Boeing says the 787's revolutionary design will save air carrers money by using less fuel.