An American official was reported by CNN to have told the network this was due to security concerns about passengers boarding direct US flights from certain countries.
The ban is said to be for a limited period which was not specified.
The US government last week announced a modified version of its ban on the movement of citizens from Muslim countries, with Iraq being removed from a list of seven countries that were included in an earlier ban. This ban, like the earlier one, has been halted by a court.
It said the advice was based on information from "concerned U.S. departments" but did not offer any further clarification.
All other devices, such as laptops, DVD players and game consoles have to be stored along with checked baggage.
Royal Jordanian flies to New York's John F. Kennedy International Airport, Chicago's O'Hare International Airport, as well Montreal and Detroit.
Dept of Homeland Security Statement: "We have no comment on potential security precautions, but will provide any update as appropriate.” https://t.co/VHqUrQyQYn— James Scott (@JamesScott2) March 20, 2017
While CNN said the Department of Homeland Security had no comment, the US State Department had confirmed that relevant countries and airlines were being informed of the device ban.