The EU is to act "very rapidly" to help airlines struggling from the new coronavirus outbreak by proposing a law to stop "ghost flights" to keep airport slots, European Commission President Ursula von der Leyen said Tuesday.

"The coronavirus outbreak had a major impact on European and international aviation industry. We see that the situation is deteriorating on a daily basis and traffic is expected to decline further," she said in a broadcast declaration.

"This is why the Commission will put forward very rapidly legislation regarding the so-called airport slots.... it will also decrease emissions by avoiding the so-called 'ghost flights' when airlines fly almost empty planes simply to keep their slot," she said.

"Slots" are reserved take-off or landing authorisations that airports allocate to airlines. Currently, if an airline does not operate a flight in its allocated slot it can lose it to a competitor.

With the abrupt drop-off in passenger numbers due to the expanding coronavirus crisis, many airlines have taken to flying empty planes -- "ghost flights" -- to ensure they do not lose their slots.

Von der Leyen's proposal means the Commission would put forward an emergency EU draft law to allow airlines to keep those slots without operating ghost flights while the virus emergency goes on.

Such legislation would have to go to the European Parliament for adoption, and then to the European Council representing the EU's 27 member states for approval.

The Commission president said this initiative was just one example of a raft of measures the EU executive was looking at to alleviate the impact of the new coronavirus, which is proving both deadly and economically damaging as it spreads.